All Calculators

521 calculators.

Math

• Basic Calculator — Evaluate an arithmetic expression with correct operator precedence.
• Circle Calculator — Find area, circumference, radius or diameter of a circle from any one measurement.
• Combination Calculator — Count unordered selections: how many ways to choose r items from n.
• Coordinate Geometry Calculator — Analyse two points at once: distance, midpoint, slope, line equation and angle.
• Cube Root Calculator — Find the cube root of any number, including negatives.
• Cubic Equation Solver — Solve ax³ + bx² + cx + d = 0 and get all three roots, real or complex.
• Decimal to Fraction Calculator — Turn any decimal into its simplest exact fraction and mixed number.
• Distance Between Two Points — Find the straight-line distance between two points in 2D or 3D space.
• Exponent Calculator — Raise any base to any power, including negative and fractional exponents.
• Factorial Calculator — Compute n! for whole numbers, with exact results for large values.
• Fraction Calculator — Add, subtract, multiply and divide two fractions, with the result fully simplified.
• Fraction to Decimal Calculator — Convert any fraction to its decimal form and detect repeating digits.
• Fraction to Percentage Calculator — Convert a fraction into a percentage and a decimal.
• GCD Calculator — Find the greatest common divisor of two or more whole numbers.
• LCM Calculator — Find the least common multiple of two or more whole numbers.
• Logarithm Calculator — Compute logarithms in any base, including natural log and log base 10.
• Mean Calculator — Find the arithmetic mean (average) of a set of numbers.
• Median Calculator — Find the middle value of a data set, plus quartiles.
• Midpoint Calculator — Find the point exactly halfway between two coordinates.
• Mixed Number Calculator — Convert between mixed numbers and improper fractions, and see the decimal.
• Mode Calculator — Find the most frequently occurring value or values in a data set.
• Modulo Calculator — Find the remainder after division, with both the programming and mathematical conventions.
• Percentage Calculator — Work out what X% of a number is, what percent one number is of another, and reverse percentages.
• Percentage Change Calculator — Measure the percentage increase or decrease between an old value and a new value.
• Percentage Decrease Calculator — Subtract a percentage from a number and see the reduction and final value.
• Percentage Difference Calculator — Compare two values of equal standing using the difference relative to their average.
• Percentage Increase Calculator — Add a percentage to a number and see the increase amount and final value.
• Permutation Calculator — Count ordered arrangements: how many ways to pick r items from n where order matters.
• Prime Factorization Calculator — Break any whole number into its prime factors with exponents.
• Prime Number Checker — Test whether a number is prime and find the nearest primes around it.
• Probability Calculator — Find single-event probability plus the odds, complement and repeated-trial chances.
• Proportion Calculator — Solve A : B = C : D for any missing value using cross multiplication.
• Pythagorean Theorem Calculator — Find any missing side of a right triangle, plus its angles, area and perimeter.
• Quadratic Equation Solver — Solve ax² + bx + c = 0, including complex roots, vertex and discriminant.
• Random Number Generator — Generate random whole numbers in a range, with or without duplicates.
• Range Calculator — Find the spread between the largest and smallest values in a data set.
• Ratio Calculator — Simplify a ratio, scale it, and solve for a missing term.
• Ratio to Percentage Calculator — Convert a ratio into percentage shares of the whole.
• Rectangle Area Calculator — Find the area, perimeter and diagonal of a rectangle or square.
• Regular Polygon Calculator — Find the area, perimeter and angles of any regular polygon.
• Roman Numeral Converter — Convert numbers to Roman numerals and Roman numerals back to numbers.
• Rounding Calculator — Round any number to decimal places, whole numbers, or the nearest multiple.
• Scientific Notation Converter — Convert between standard decimal form, scientific notation and engineering notation.
• Significant Figures Calculator — Round to a chosen number of significant figures and count the sig figs in a value.
• Slope Calculator — Find the slope, angle and equation of the line through two points.
• Square Root Calculator — Find the square root of any number, plus the simplified radical form.
• Standard Deviation Calculator — Compute standard deviation, variance, mean and the full set of descriptive statistics.
• Surface Area Calculator — Find the surface area of common 3D shapes for painting, coating or wrapping.
• Trapezoid Area Calculator — Find the area of a trapezoid from its two parallel sides and height.
• Triangle Area Calculator — Find a triangle's area from base and height, three sides, or two sides and the angle between.
• Variance Calculator — Calculate population and sample variance for a data set.
• Volume Calculator — Find the volume of a box, cylinder, sphere, cone, pyramid or capsule.
• Weighted Average Calculator — Average values where each carries a different weight or importance.

Percentage & Everyday

• Commission Calculator — Calculate commission earnings including tiered rates and a base salary.
• Currency Converter — Convert between currencies using a rate you supply, including bank margin and fees.
• Discount Calculator — Find the sale price and money saved from a percentage discount, including stacked offers.
• Fuel Cost Calculator — Estimate the fuel cost of a trip and the cost per mile or kilometre.
• Fuel Efficiency Calculator — Calculate your real-world fuel economy from distance travelled and fuel used.
• Grade Percentage Calculator — Turn marks scored out of a total into a percentage, a letter grade and a pass or fail verdict.
• GST Calculator — Add GST to a net price or work backwards from a GST-inclusive total, at any rate, with the tax shown separately.
• Markup Calculator — Calculate selling price from cost and markup, and see the resulting margin.
• Price Per Unit Calculator — Convert a package price into price per gram, kilogram, litre, ounce or item.
• Sale Price Calculator — Work out the original price from a sale price, or the discount percentage from both.
• Sales Tax Calculator — Add sales tax to a price or extract the tax from a tax-inclusive total.
• Split Bill Calculator — Split a bill evenly or by individual spend, with tip and tax handled fairly.
• Test Score Calculator — Find your score from questions answered correctly, with grading curve options.
• Tip Calculator — Calculate a tip and split the total between any number of people.
• Unit Price Calculator — Compare products by price per unit to find which is genuinely better value.
• VAT Calculator — Add VAT to a net price or strip it back out of a gross price, at any rate, showing the tax amount separately.

Finance

• Annual Compound Interest Calculator — Calculate growth when interest compounds once per year.
• Annuity Calculator — Value a stream of equal payments, or find the payment a lump sum can sustain.
• APY Calculator — Convert a nominal interest rate into annual percentage yield and back.
• Bonus Calculator — Calculate a performance bonus and what lands in your pocket after tax.
• Break-Even Calculator — Find the sales volume and revenue needed to cover all your costs.
• Business Loan Calculator — Calculate business loan repayments and check them against your cash flow.
• CAGR Calculator — Find the compound annual growth rate between a starting and ending value.
• Car Loan Calculator — Work out car finance payments including trade-in, down payment and sales tax.
• Compound Interest Calculator — See how money grows when interest earns interest, with optional regular contributions.
• Credit Card Interest Calculator — Calculate the daily and monthly interest charged on a card balance.
• Credit Card Payoff Calculator — Find out how long your card takes to clear and what it truly costs.
• Daily Compound Interest Calculator — Calculate growth when interest compounds every day.
• Debt Payoff Calculator — See how long a debt takes to clear and how much extra payments save you.
• Debt-to-Income Ratio Calculator — Calculate the DTI ratio lenders use to decide how much you can borrow.
• Effective Interest Rate Calculator — Turn a nominal rate into its true effective annual rate under any compounding schedule.
• Emergency Fund Calculator — Work out how large your emergency fund should be and how long it will take to build.
• EMI Calculator — Work out a monthly instalment on a reducing-balance basis, and compare it against the same rate quoted flat.
• Future Value Calculator — Find what a sum today will be worth in the future, with optional periodic payments.
• Home Loan Calculator — Work back from a property price and deposit to the loan, its lifetime interest cost and what overpaying saves.
• Hourly to Salary Calculator — Convert an hourly wage into weekly, monthly and annual salary.
• Inflation Calculator — See how inflation changes purchasing power over time, forwards or backwards.
• Interest Calculator — Compare simple and compound interest on the same principal side by side.
• Investment Calculator — Project an investment forward with regular contributions, and see it in real terms after inflation.
• IRR Calculator — Find the internal rate of return — the discount rate that makes NPV zero.
• Loan Calculator — Work out the instalment on any amortizing loan, at monthly, fortnightly, weekly or quarterly repayments.
• Lumpsum Investment Calculator — Project the future value of a one-time investment.
• Markup vs Margin Calculator — Convert between markup and margin percentages and see them side by side.
• Monthly Compound Interest Calculator — Calculate growth when interest compounds every month.
• Mortgage Calculator — Estimate your full monthly housing payment including taxes, insurance and down payment.
• NPV Calculator — Discount a series of cash flows to present value and decide whether a project creates value.
• Overtime Pay Calculator — Calculate overtime pay at time-and-a-half, double time or a custom multiplier.
• Pension Calculator — Estimate the pension pot you will build and the income it can provide.
• Personal Loan Calculator — Estimate personal loan payments including origination fees and the true APR.
• Present Value Calculator — Find what a future sum or stream of payments is worth in today's money.
• Profit Margin Calculator — Calculate profit margin, markup and the selling price you need to hit a target margin.
• Retirement Calculator — Project your retirement savings and check whether they will last through retirement.
• ROI Calculator — Calculate return on investment as a percentage, with annualized return if you supply a holding period.
• Rule of 72 Calculator — Estimate how long money takes to double, or what rate you need to double it in a given time.
• Salary Calculator — Convert pay between hourly, daily, weekly, monthly and annual figures.
• Salary to Hourly Calculator — Find your true hourly rate from an annual salary, including unpaid overtime.
• Savings Calculator — Plan a savings goal: see what regular deposits grow to, or what you need to save each month.
• Simple Interest Calculator — Calculate interest charged on the principal only, with no compounding.
• SIP Calculator — Project the maturity value of a Systematic Investment Plan, with optional annual step-up.
• Student Loan Calculator — Project student loan repayments, including interest that accrues while studying.
• Take-Home Pay Calculator — Estimate net pay after tax and deductions using rates you supply.

Investment

• Annualized Return Calculator — Convert a total return over any period into an equivalent annual rate.
• Asset Allocation Calculator — Suggest a stock and bond split based on age and risk tolerance.
• Bond Duration Calculator — Calculate Macaulay and modified duration to measure interest rate sensitivity.
• Bond Price Calculator — Calculate a bond price from its coupon, yield and time to maturity.
• Bond Yield Calculator — Calculate current yield and yield to maturity from a bond price.
• Inflation-Adjusted Return Calculator — Convert a nominal return into a real return after inflation.
• Investment Fee Calculator — See how much management fees cost you over the life of an investment.
• Investment Growth Calculator — Project investment growth year by year, with contributions that can step up annually — see the full compounding schedule, not just the final number.
• Portfolio Allocation Calculator — See current portfolio weights and the drift from your target allocation.
• Portfolio Rebalancing Calculator — Work out exactly what to buy and sell to return to your target allocation.
• Portfolio Return Calculator — Calculate the weighted return of a portfolio from its holdings.
• Portfolio Risk Calculator — Calculate portfolio volatility from asset volatilities, weights and correlation.
• Total Return Calculator — Combine capital growth and income into a single total return figure.

Stock Market

• Capital Gains Calculator — Calculate capital gain or loss on an investment and the tax at a rate you supply.
• Dividend Calculator — Calculate dividend income per period and the yield on your holding.
• Dividend Growth Calculator — Project dividend income as the payout grows each year.
• Dividend Reinvestment Calculator (DRIP) — Model a DRIP where dividends buy more shares, compounding your income.
• Dividend Yield Calculator — Calculate dividend yield, payout ratio and yield on cost.
• Stock Average Price Calculator — Find your average cost per share across multiple purchases.
• Stock Position Size Calculator — Work out how many shares to buy for a given risk and stop-loss.
• Stock Profit/Loss Calculator — Calculate profit or loss on a share trade after commission, including dividends received.
• Stock Return Calculator — Calculate total and annualised return on a share holding including dividends.

Trading

• Break-Even Win Rate Calculator — Find the win rate a reward-to-risk ratio needs just to break even.
• Calmar Ratio Calculator — Compare annualised return against maximum drawdown.
• Drawdown Calculator — Measure peak-to-trough decline and the gain needed to recover from it.
• Kelly Criterion Calculator — Calculate the mathematically optimal position size for long-run capital growth.
• Leverage Calculator — Calculate effective leverage, margin required and how far price can move before a margin call.
• Margin Calculator — Calculate required margin, free margin and margin level for an open position.
• Maximum Risk Calculator — Check total portfolio exposure across open positions against your risk limits.
• Position Size Calculator — Work out how many units to trade so a stop-loss hit costs exactly your intended risk.
• Profit Factor Calculator — Measure gross profit against gross loss to judge a strategy at a glance.
• R-Multiple Calculator — Measure trade outcomes in units of initial risk, and total a series.
• Risk of Ruin Calculator — Estimate the probability of losing your account given your edge and risk per trade.
• Risk/Reward Ratio Calculator — Calculate the risk/reward ratio of a trade and the win rate it needs to break even.
• Scaling In and Out Calculator — Find your average entry across tranches, or realised profit when scaling out.
• Sharpe Ratio Calculator — Measure risk-adjusted return, from summary figures or a return series.
• Stop-Loss Calculator — Find the stop-loss price for a given risk amount, percentage or position size.
• Take-Profit Calculator — Find the take-profit price from a target ratio, percentage or profit amount.
• Trading Break-Even Calculator — Find the exit price at which a trade covers all its costs.
• Trading Commission Calculator — Calculate broker commission on a trade under percentage, flat or tiered structures.
• Trading Expectancy Calculator — Calculate the average amount a strategy makes or loses per trade.
• Trading Fees Calculator — Total the commission, spread and slippage costs on a round-trip trade.
• Trading Profit/Loss Calculator — Calculate profit or loss on a long or short trade after fees and commission.
• Win Rate Calculator — Calculate your win rate, loss rate and how it compares to what your strategy needs.

Forex

• Forex Account Risk Calculator — Check total risk across open forex positions against your account limit.
• Forex Break-Even Calculator — Find the price at which a forex trade covers spread, commission and swap.
• Forex Commission Calculator — Calculate broker commission per lot and the total cost of a round turn.
• Forex Currency Conversion Calculator — Convert a trade amount between currencies at a rate you supply, including exchange margin — for sizing forex positions, not everyday spending.
• Forex Free Margin Calculator — Find how much margin remains available for new positions.
• Forex Leverage Calculator — Calculate real leverage on your account and the exposure it creates.
• Forex Lot Size Calculator — Convert between units, standard lots, mini lots, micro lots and nano lots.
• Forex Margin Calculator — Calculate the margin required to open a forex position at a given leverage.
• Forex Margin Level Calculator — Calculate margin level and see how close you are to a margin call or stop-out.
• Forex Pip Calculator — Count the pips between two prices and convert them into profit or loss.
• Forex Pip Risk Calculator — Convert a stop-loss in pips into a currency risk and percentage of your account.
• Forex Pip Value Calculator — Calculate the monetary value of one pip for any pair, lot size and account currency.
• Forex Position Size Calculator — Calculate the lot size that risks exactly your chosen percentage on a given stop.
• Forex Position Value Calculator — Calculate the notional value of a forex position in base, quote and account currency.
• Forex Profit/Loss Calculator — Calculate profit or loss on a forex trade including spread and commission.
• Forex Risk/Reward Calculator — Compare stop and target distances in pips and see the win rate needed.
• Forex Spread Cost Calculator — Calculate what the bid-ask spread costs on a trade, and across a year of trading.
• Forex Stop-Loss Calculator — Find the stop-loss price in pips and price terms for a chosen risk.
• Forex Swap Calculator — Calculate overnight swap or rollover charges on a position held over days.
• Forex Take-Profit Calculator — Find the take-profit price from a pip target, ratio or profit amount.
• Forex Trading Cost Calculator — Total every cost on a forex trade — spread, commission and swap combined.
• Forex Trading Return Calculator — Calculate percentage return on a forex account over a period, annualised.

Cryptocurrency

• Crypto APR Calculator — Calculate the simple annual rate earned on a crypto position over a period.
• Crypto APY Calculator — Convert between APR and APY for staking, lending and yield farming.
• Crypto Average Price Calculator — Find your average entry price across multiple buys at different prices.
• Crypto Break-Even Calculator — Find the price at which a crypto position covers its cost and fees.
• Crypto Compound Interest Calculator — Project compounded crypto yields with optional recurring deposits.
• Crypto Conversion Calculator — Convert between two crypto assets or crypto and fiat at rates you supply.
• Crypto DCA Calculator — Model a dollar-cost averaging plan and see the accumulated position and return.
• Crypto Funding Rate Calculator — Calculate funding payments on a perpetual futures position over time.
• Crypto Futures P&L Calculator — Calculate profit, ROE and fees on a leveraged crypto futures position.
• Crypto Gas Fee Calculator — Calculate Ethereum-style transaction costs from gas price and gas limit.
• Crypto Investment Calculator — Project what a crypto investment could be worth at a target price.
• Crypto Leverage Calculator — Calculate leveraged exposure, margin and the move that wipes out your position.
• Crypto Liquidation Distance Calculator — Measure how far the price can move before your leveraged position is liquidated.
• Crypto Liquidation Price Calculator — Find the price at which a leveraged crypto position gets liquidated.
• Crypto Margin Calculator — Calculate initial and maintenance margin for a leveraged crypto position.
• Crypto Margin Level Calculator — Check your margin ratio and how close the position is to liquidation.
• Crypto Mining Profitability Calculator — Calculate mining revenue, electricity cost and payback period on hardware.
• Crypto Portfolio Allocation Calculator — See your portfolio weights and what to trade to reach target allocations.
• Crypto Portfolio Profit Calculator — Calculate total profit and return across every holding in your portfolio.
• Crypto Position Size Calculator — Calculate the position size that risks a fixed percentage of your account.
• Crypto Profit/Loss Calculator — Calculate profit or loss on a crypto trade after exchange fees.
• Crypto Risk/Reward Calculator — Compare risk and reward on a crypto trade and find the win rate needed.
• Crypto ROI Calculator — Calculate return on a crypto investment, including the annualised rate.
• Crypto Staking Break-Even Calculator — Find how long staking rewards take to cover hardware and running costs.
• Crypto Staking Rewards Calculator — Project staking rewards with compounding, in both coins and currency.
• Crypto Stop-Loss Calculator — Set a stop-loss price from a percentage or a fixed risk amount.
• Crypto Take-Profit Calculator — Set a take-profit price from a percentage gain, ratio or target amount.
• Crypto Tax Calculator — Estimate capital gains tax owed on crypto disposals at a rate you supply.
• Crypto Trading Fee Calculator — Calculate exchange fees on a trade and across a year of trading.

Tax

• Business Tax Calculator — Estimate corporate tax on business profit, with deductions and loss carry-forward.
• Capital Gains Tax Calculator — Calculate tax on an asset sale, with separate short-term and long-term rates.
• Effective Tax Rate Calculator — Find the actual percentage of your income that goes to tax.
• Income Tax Calculator — Calculate income tax using progressive brackets you supply, with effective and marginal rates.
• Investment Tax Calculator — Calculate tax across dividends, interest and capital gains at their separate rates.
• Marginal Tax Rate Calculator — Find the tax rate on your next unit of income, and what a raise is really worth.
• Payroll Tax Calculator — Calculate employee and employer payroll contributions with wage caps.
• Property Tax Calculator — Calculate annual property tax from assessed value, rate and exemptions.
• Salary Tax Calculator — Full salary breakdown: income tax by bracket, payroll contributions and net pay.
• Tax Bracket Calculator — See exactly how much tax each bracket contributes and where you sit within your band.
• Tax Deduction Calculator — See what a deduction actually saves you at your marginal rate.
• Tax Refund Calculator — Estimate whether you are due a refund or owe more tax.
• TDS Calculator — Calculate tax deducted at source and the net amount received.

Real Estate

• Cap Rate Calculator — Calculate capitalisation rate and implied property value from net operating income.
• Cash-on-Cash Return Calculator — Measure annual cash flow against the actual cash you invested.
• Construction Cost per Square Foot Calculator — Estimate build cost from area and rate, with contingency and soft costs.
• Down Payment Calculator — Work out the deposit needed and how long it takes to save it.
• House Affordability Calculator — Find the house price you can afford using lender debt-to-income rules.
• Mortgage Affordability Calculator — Check whether a specific property fits within lender affordability limits.
• Property Appreciation Calculator — Project future property value and the equity growth it produces.
• Property Flip Profit Calculator — Calculate profit on a buy-renovate-sell project including holding and financing costs.
• Property Investment Calculator — Full investment analysis: cash flow, yield, cap rate and projected returns together.
• Real Estate Commission Calculator — Calculate agent commission and the seller net proceeds after all costs.
• Real Estate ROI Calculator — Total return on a property including cash flow, appreciation and principal paydown.
• Rent vs Buy Calculator — Compare the total cost of renting against buying over a holding period.
• Rental Income Calculator — Project net rental income after every operating cost and mortgage.
• Rental Yield Calculator — Calculate gross and net rental yield on an investment property.
• Stamp Duty Calculator — Calculate transfer tax on a property purchase using tiered bands you supply.

Date & Time

• Age Calculator — Calculate exact age in years, months and days, plus total days, hours and minutes.
• Birthday Countdown Calculator — Count down to your next birthday and see the age you will turn.
• Business Days Calculator — Count working days between two dates, excluding weekends and holidays.
• Countdown Calculator — Count down to any future date in days, weeks, hours and business days.
• Date Add / Subtract Calculator — Add or subtract days, weeks, months or years from any date.
• Date Difference Calculator — Find the time between two dates in years, months, days, weeks and business days.
• Day of the Week Calculator — Find which day of the week any date falls on, past or future.
• Days in Year Calculator — Find how many days, weeks and working days a year contains.
• Leap Year Calculator — Check whether a year is a leap year and find the leap years around it.
• Time Card Calculator — Total a weekly timesheet from daily clock-in and clock-out times.
• Time Difference Calculator — Add or subtract hours, minutes and seconds, or find the gap between two times.
• Time Duration Calculator — Calculate the duration between two times, with optional break deduction.
• Unix Timestamp Converter — Convert between Unix timestamps and human-readable dates.
• Week Number Calculator — Find the ISO week number for a date, or the dates in a given week.
• Work Hours Calculator — Total weekly work hours and pay, including overtime above a threshold.

Health & Fitness

• BMI Calculator — Calculate body mass index and see where it falls on the WHO classification.
• BMR Calculator — Calculate basal metabolic rate — the calories you burn at complete rest.
• Body Fat Calculator — Estimate body fat percentage using the US Navy tape measurement method.
• Body Surface Area Calculator — Calculate body surface area using the Du Bois, Mosteller and Haycock formulas.
• Calorie Calculator — Find your daily calorie target for losing, maintaining or gaining weight.
• Calorie Deficit Calculator — Work out the deficit you need to hit a weight loss goal by a target date.
• Carbohydrate Intake Calculator — Work out daily carbohydrate needs from body weight and training load.
• Heart Rate Zone Calculator — Calculate your maximum heart rate and the five training zones.
• Ideal Weight Calculator — Estimate a healthy weight range using four established clinical formulas.
• Lean Body Mass Calculator — Calculate lean body mass and fat mass from weight and body fat percentage.
• Macro Calculator — Split your daily calories into protein, carbohydrate and fat targets.
• One Rep Max Calculator — Estimate your 1RM from a submaximal set and get a full percentage training table.
• Protein Calculator — Find your daily protein target based on body weight and training goals.
• Running Calories Calculator — Estimate calories burned running, adjusted for pace, weight and incline.
• Running Pace Calculator — Calculate pace, time or distance, with split times for common race distances.
• TDEE Calculator — Calculate total daily energy expenditure — the calories you burn in a full day.
• VO₂ Max Calculator — Estimate aerobic fitness from a resting heart rate, a 1.5-mile run or the Cooper test.
• Waist-to-Height Ratio Calculator — Assess health risk from central body fat using waist circumference and height.
• Waist-to-Hip Ratio Calculator — Calculate WHR and assess body fat distribution and associated health risk.
• Water Intake Calculator — Estimate how much water to drink daily based on weight, activity and climate.
• Weight Loss Calculator — Project how long a goal will take at your current calorie intake.

Unit Converters

• Acceleration Converter — Convert acceleration between m/s², ft/s², g-force, gal and standard gravity, with exact conversion factors.
• Angle Converter — Convert between degrees, radians, gradians and turns.
• Area Converter — Convert between square metres, square feet, acres, hectares and more.
• Bandwidth Converter — Convert between bits per second, megabits, megabytes per second and more.
• Cooking Measurement Converter — Convert between cups, tablespoons, teaspoons, millilitres and fluid ounces.
• Data Storage Converter — Convert between bytes, kilobytes, megabytes, gigabytes and terabytes.
• Density Converter — Convert between kg/m³, g/cm³, lb/ft³ and other density units.
• Electrical Charge & Current Converter — Convert between amperes, milliamperes, coulombs and amp-hours.
• Energy Converter — Convert between joules, calories, kilowatt-hours, BTU and electronvolts.
• Flow Rate Converter — Convert between litres per minute, cubic metres per hour, GPM and CFM.
• Force Converter — Convert between newtons, pounds-force, kilograms-force and dynes.
• Frequency Converter — Convert between hertz, kilohertz, megahertz, gigahertz and RPM.
• Fuel Economy Converter — Convert between mpg, litres per 100 km and km per litre.
• Illumination Converter — Convert between lux, foot-candles, lumens per square metre and phot.
• Length Converter — Convert between metres, feet, inches, miles, kilometres and more.
• Power Converter — Convert between watts, kilowatts, horsepower and BTU per hour.
• Pressure Converter — Convert between pascals, bar, psi, atmospheres and mmHg.
• Speed Converter — Convert between km/h, mph, m/s, knots and the speed of light.
• Temperature Converter — Convert between Celsius, Fahrenheit, Kelvin and Rankine.
• Time Converter — Convert between seconds, minutes, hours, days, weeks, months and years.
• Torque Converter — Convert between newton-metres, foot-pounds and inch-pounds.
• Typography Converter — Convert between points, pixels, ems, picas, inches and millimetres.
• Volume Converter — Convert between litres, gallons, cubic metres, cups, pints and more.
• Weight & Mass Converter — Convert between kilograms, pounds, ounces, stones, tonnes and grams.

Construction & Home

• Brick Calculator — Calculate bricks and mortar needed for a wall, including openings.
• Cement Calculator — Work out cement bags, sand and aggregate for a given volume and mix ratio.
• Concrete Block Calculator — Work out how many concrete blocks, how much mortar and how many bags of mix a wall needs, including waste.
• Concrete Calculator — Calculate concrete volume for slabs, footings and columns, with cement, sand and aggregate quantities.
• Concrete Slab Calculator — Calculate concrete, mesh and formwork for a floor slab.
• Deck Calculator — Calculate decking boards, joists and fixings for a deck.
• Driveway Calculator — Calculate materials for a driveway including sub-base and surface layers.
• Excavation Calculator — Calculate excavation volume, truck loads and disposal for trenches and pits.
• Fence Calculator — Calculate posts, panels, rails and concrete for a fence run.
• Flooring Calculator — Calculate flooring area, packs needed and cost for any room shape.
• Footing Calculator — Calculate concrete for strip footings, pad foundations and pier holes.
• Gravel Calculator — Calculate gravel or aggregate volume, weight and cost for a given area and depth.
• Lumber Calculator — Calculate board feet, linear metres, piece counts and cost for timber.
• Mortar Calculator — Calculate mortar volume, cement and sand for brickwork or blockwork.
• Paint Calculator — Calculate paint needed for walls and ceilings, allowing for doors, windows and multiple coats.
• Plaster Calculator — Calculate plaster or render quantities for walls and ceilings.
• Rebar Calculator — Calculate reinforcing bar length, count and weight for a slab grid.
• Retaining Wall Calculator — Calculate blocks, concrete footing and backfill for a retaining wall.
• Roofing Calculator — Calculate roof area from pitch and footprint, plus tiles or sheets needed.
• Room Area Calculator — Calculate floor, wall and ceiling areas plus room volume.
• Sand Calculator — Calculate sand volume, weight and bags for bedding, screed or fill.
• Soil & Topsoil Calculator — Calculate topsoil, compost or mulch volume and weight for beds and lawns.
• Stair Calculator — Calculate rise, going, stair length and check against building regulations.
• Steel Weight Calculator — Calculate the weight of steel bars, plates, tubes and sections.
• Tile Calculator — Calculate how many tiles, adhesive and grout you need for floors or walls.
• Wall Area Calculator — Calculate wall area, studs, plasterboard sheets and insulation.

Electrical

• Amps to Watts Calculator — Convert current in amps to power in watts for AC or DC circuits.
• Appliance Running Cost Calculator — Compare the running cost of several appliances side by side.
• Battery Capacity Calculator — Size a battery bank for a required runtime and load.
• Battery Runtime Calculator — Calculate how long a battery will power a load, allowing for depth of discharge.
• Electrical Power Calculator — Calculate real, apparent and reactive power for single or three-phase supplies.
• Electricity Bill Calculator — Estimate a full electricity bill including tiered rates, standing charge and tax.
• Electricity Cost Calculator — Calculate the running cost of any appliance by hour, day, month and year.
• Generator Size Calculator — Size a standby generator for running and starting loads.
• Inverter Size Calculator — Size an inverter for continuous and surge loads with headroom.
• kWh Calculator — Convert between watts, kilowatts, kilowatt-hours and energy cost.
• Motor Current Calculator — Calculate full-load and starting current for an electric motor.
• Ohm's Law Calculator — Solve for voltage, current, resistance or power from any two known values.
• Power Factor Calculator — Calculate power factor and the correction capacitance needed to improve it.
• Resistor Calculator — Calculate series and parallel resistance, and voltage divider outputs.
• Three-Phase Power Calculator — Calculate three-phase power, current and line values for star or delta.
• Voltage Drop Calculator — Calculate voltage drop over a cable run and check it against limits.
• Volts to Watts Calculator — Calculate power from voltage with either current or resistance.
• Watts to Amps Calculator — Convert power in watts to current in amps for AC or DC circuits.
• Wire Size Calculator — Estimate cable cross-section from voltage drop and load — a planning figure, not a compliant selection.

Energy & Solar

• Battery Backup Calculator — Work out how long a battery will run your essential loads during an outage.
• Electricity Carbon Footprint Calculator — Calculate CO₂ emissions from electricity use and the savings from solar.
• Energy Consumption Calculator — Audit household energy use by adding up appliance loads and running hours.
• Energy Cost Comparison Calculator — Compare heating fuels on a like-for-like cost per useful kWh.
• Net Metering Calculator — Calculate your net electricity bill with solar export credits.
• Solar Battery Calculator — Size a home battery to store solar surplus and cut evening grid imports.
• Solar Inverter Sizing Calculator — Size a solar inverter using the DC-to-AC ratio and check for clipping.
• Solar Panel Calculator — Work out how many solar panels you need to cover your electricity use.
• Solar Panel Output Calculator — Estimate daily, monthly and annual generation from a solar array.
• Solar Payback Calculator — Find how long a solar system takes to pay for itself.
• Solar ROI Calculator — Calculate return on investment and levelised cost of energy for a solar system.
• Solar Roof Area Calculator — Find how much solar capacity fits on your roof, or the area a system needs.
• Solar Savings Calculator — Estimate annual and lifetime bill savings from a solar system.
• Solar System Size Calculator — Calculate the kW solar system size needed for your electricity consumption.
• Wind Turbine Output Calculator — Estimate energy output from a wind turbine using rotor size and wind speed.

Science

• Acceleration Calculator — Calculate acceleration from a velocity change, from force and mass, or from distance.
• Buoyancy Calculator — Apply Archimedes’ principle to find buoyant force and whether an object floats.
• Centripetal Force Calculator — Calculate the force and acceleration needed to keep an object moving in a circle.
• Density Calculator — Calculate density, mass or volume, and check whether something floats.
• Force Calculator — Apply Newton’s second law to find force, mass or acceleration.
• Free Fall Calculator — Calculate fall time, distance and impact speed under gravity.
• Gravitational Force Calculator — Apply Newton’s law of gravitation, or find surface gravity and escape velocity.
• Half-Life Calculator — Calculate radioactive decay: how much remains, how long it takes, or the half-life.
• Ideal Gas Law Calculator — Solve PV = nRT for pressure, volume, moles or temperature.
• Kinetic Energy Calculator — Calculate the energy of a moving object, or the speed for a given energy.
• Molarity Calculator — Calculate solution molarity, the mass needed, or a dilution.
• Momentum Calculator — Calculate momentum and impulse, and the force a collision delivers.
• pH Calculator — Convert between pH, pOH and hydrogen ion concentration.
• Photon Energy Calculator — Calculate photon energy from wavelength or frequency, in joules and electronvolts.
• Potential Energy Calculator — Calculate gravitational potential energy, or the energy stored in a spring.
• Pressure Calculator — Calculate pressure from force over area, or the pressure at depth in a fluid.
• Projectile Motion Calculator — Find the range, peak height and flight time of a launched projectile.
• Snell’s Law Calculator — Calculate the refraction angle at a boundary, and find the critical angle.
• Specific Heat Calculator — Calculate the heat energy needed to change a material’s temperature.
• Torque Calculator — Calculate torque from force and lever arm, or the force a given torque needs.
• Velocity Calculator — Find velocity from distance and time, or from acceleration using the kinematic equations.
• Wave Speed Calculator — Calculate wave speed from frequency and wavelength, for sound, light or any wave.
• Wavelength Calculator — Find wavelength from frequency, and identify where it sits on the spectrum.
• Work and Power Calculator — Calculate mechanical work from force and distance, and the power it takes.

Statistics & Data

• Binomial Probability Calculator — Find the probability of a number of successes in a fixed number of trials.
• Chi-Square Calculator — Run a chi-square goodness-of-fit test on observed versus expected counts.
• Coefficient of Variation Calculator — Compare relative variability between data sets with different units or scales.
• Confidence Interval Calculator — Build a confidence interval for a mean or a proportion.
• Correlation Coefficient Calculator — Calculate Pearson correlation between two variables, with significance testing.
• Covariance Calculator — Calculate sample and population covariance between two variables.
• Exponential Distribution Calculator — Find probabilities for waiting times between events.
• Geometric Mean Calculator — Calculate the geometric mean, the correct average for growth rates and ratios.
• Harmonic Mean Calculator — Calculate the harmonic mean, the correct average for rates and speeds.
• Interquartile Range Calculator — Find the quartiles and interquartile range of a data set, and flag outliers using the 1.5 × IQR rule.
• Linear Regression Calculator — Fit a least-squares line, with slope, intercept, r² and prediction.
• Margin of Error Calculator — Calculate the margin of error for a survey result.
• Normal Distribution Calculator — Find probabilities and z-scores for any normal distribution.
• Percentile Calculator — Find any percentile of a data set, or the percentile rank of a value.
• Poisson Distribution Calculator — Find the probability of a number of events in a fixed interval.
• Quartile Calculator — Find Q1, Q2, Q3, the interquartile range and any outliers.
• Sample Size Calculator — Find the sample size needed for a target margin of error.
• Standard Error Calculator — Calculate the standard error of the mean and its confidence interval.
• T-Test Calculator — Run a one-sample or two-sample t-test and get the p-value.
• Z-Score Calculator — Convert a value to a z-score and find its percentile in a normal distribution.

Education

• Attendance Calculator — Track your attendance percentage and how many classes you can still miss.
• CGPA Calculator — Calculate CGPA on the 10-point scale and convert it to a percentage.
• Class Rank Percentile Calculator — Convert a class rank into a percentile and see where you sit in the cohort.
• Credit Hours Calculator — Work out your course load, tuition cost and time to finish a degree.
• Cumulative GPA Calculator — Combine your prior GPA with a new term, and see what you need next.
• Essay Length Calculator — Convert between essay word count, page count and reading time.
• Exam Average Calculator — Average a set of test scores, with the option to drop the lowest results.
• Final Grade Calculator — Find the score you need on the final exam to reach your target grade.
• GPA Calculator — Calculate your grade point average from course grades and credit hours.
• Grade Curve Calculator — Apply a curve to a set of class scores and compare the methods.
• Percentage to GPA Calculator — Convert between percentage, letter grade, 4.0 GPA and 10-point CGPA.
• Points-Based Grade Calculator — Total up points earned across every assignment to find your course grade.
• Reading Time Calculator — Estimate how long a text takes to read silently or aloud.
• Study Time Calculator — Plan study hours from your course load, or spread revision across the days left.
• Weighted Grade Calculator — Combine assignment categories by their syllabus weights into a course grade.

Business

• Accounts Receivable Calculator — Calculate days sales outstanding and the cash tied up in unpaid invoices.
• ARR Calculator — Calculate annual recurring revenue and project it forward at a growth rate.
• Burn Rate Calculator — Calculate gross and net burn, and how long your cash will last.
• CAC Payback Period Calculator — Find how long it takes to recover the cost of acquiring a customer.
• Cash Runway Calculator — Find how many months of cash you have left and when to start fundraising.
• Churn Rate Calculator — Calculate customer and revenue churn, and the lifespan they imply.
• Conversion Rate Calculator — Calculate conversion rate and the revenue impact of improving it.
• Customer Acquisition Cost (CAC) Calculator — Calculate what it costs to acquire one customer across sales and marketing.
• Customer Lifetime Value (LTV) Calculator — Estimate the total profit a customer generates over their relationship with you.
• EBITDA Calculator — Calculate EBITDA and EBITDA margin from either direction.
• Gross Margin Calculator — Calculate gross profit and gross margin from revenue and cost of goods sold.
• Inventory Turnover Calculator — Measure how quickly inventory sells and how many days of stock you hold.
• Invoice Calculator — Build an invoice total with tax, discount, shipping and early-payment terms.
• LTV:CAC Ratio Calculator — Compare customer lifetime value against acquisition cost to judge unit economics.
• Marketing ROI Calculator — Measure the profit generated per unit of marketing spend.
• MRR Calculator — Calculate monthly recurring revenue and break it into growth components.
• Net Profit Margin Calculator — Calculate the percentage of revenue that becomes net profit.
• Operating Margin Calculator — Measure profitability from core operations, before interest and tax.
• Profit Calculator — Calculate gross, operating and net profit from revenue and costs.
• Retail Price Calculator — Set a retail price from cost, target margin, overheads and expected discounting.
• Retention Rate Calculator — Calculate customer retention and project how a cohort decays over time.
• Revenue Growth Calculator — Calculate period-on-period growth rates and project revenue forward.
• ROAS Calculator — Calculate return on ad spend and the break-even ROAS your margin requires.
• Sales Commission Calculator — Calculate tiered sales commission across multiple brackets with quota attainment.
• Wholesale Price Calculator — Set wholesale and retail prices from your unit cost and target margins.

Automotive & Transport

• Car Affordability Calculator — Work out how much car you can afford from a monthly budget or your income.
• Car Depreciation Calculator — Project what a vehicle will be worth after any number of years.
• Car Lease Calculator — Calculate a monthly lease payment from cap cost, residual and money factor.
• Compression Ratio Calculator — Calculate compression ratio from swept and clearance volume, or work backwards.
• Cost Per Mile Calculator — Add up every running cost to find what each mile really costs you.
• Engine Displacement Calculator — Calculate engine capacity from bore, stroke and cylinder count.
• EV Charging Cost Calculator — Calculate what it costs and how long it takes to charge an electric car.
• EV Range Calculator — Estimate real electric range after weather, speed and battery derating.
• EV vs Gas Calculator — Compare running costs of an electric car against petrol, and find the break-even.
• Fuel Savings Calculator — Compare two vehicles’ fuel costs and see what switching would save.
• Gear Ratio Calculator — Find road speed at any engine speed, or the revs at a given speed.
• Horsepower Calculator — Calculate horsepower from torque and RPM, or estimate it from quarter-mile times.
• Lease vs Buy Calculator — Compare the true cost of leasing against financing the same car.
• Road Trip Calculator — Plan driving time, fuel cost and overnight stops for a long journey.
• Tire Size Calculator — Compare two tyre sizes and find the speedometer error from changing them.
• Towing Capacity Calculator — Check payload, tongue weight and the real limit on what you can tow.

Programming & Tech

• Aspect Ratio Calculator — Find the aspect ratio of a resolution and scale it to new dimensions.
• Bandwidth Calculator — Size the bandwidth and monthly transfer a service needs.
• Base64 Size Calculator — Calculate the encoded size and overhead of Base64 data.
• Big O Complexity Calculator — Compare how algorithm complexity classes scale with input size.
• Bitwise Calculator — Apply AND, OR, XOR, NOT and shift operations at any bit width.
• Color Contrast Calculator — Check WCAG contrast ratio between two colours for accessibility.
• Color Converter — Convert a colour between HEX, RGB, HSL and CMYK, with the equivalent values shown in every format at once.
• Download Time Calculator — Work out how long a file takes to transfer at a given connection speed.
• Hash Collision Probability Calculator — Calculate collision odds for a hash or ID space using the birthday problem.
• IEEE 754 Floating Point Calculator — See how a decimal number is stored as a 32 or 64-bit float, and its error.
• IP Subnet Calculator — Calculate network address, broadcast, mask and usable host range from CIDR.
• Number Base Converter — Convert numbers between binary, octal, decimal, hexadecimal and any base.
• Password Entropy Calculator — Measure password strength in bits of entropy and estimate crack time.
• Throughput and Latency Calculator — Apply Little’s Law to relate throughput, latency and concurrency.
• Two's Complement Calculator — Convert between signed decimal values and their binary representation.
• Uptime SLA Calculator — Convert an availability percentage into allowed downtime per day, month and year.

Cooking & Food

• Baker's Percentage Calculator — Express a bread formula as percentages of flour, or work back from a dough weight.
• Brine Calculator — Calculate salt for a wet brine, equilibrium brine or dry cure.
• Cake Pan Conversion Calculator — Adjust a recipe when swapping to a different size or shape of tin.
• Coffee Ratio Calculator — Calculate coffee and water for any brew ratio and batch size.
• Dough Hydration Calculator — Calculate dough hydration, including flour and water carried in a starter.
• Food Cost Calculator — Work out cost per serving, food cost percentage and a menu price.
• Oven Temperature Calculator — Convert oven temperatures between Celsius, Fahrenheit, gas mark and fan.
• Pizza Dough Calculator — Calculate flour, water, salt and yeast for any number of pizza bases.
• Recipe Scaling Calculator — Scale a recipe up or down for a different number of servings.
• Rice Water Ratio Calculator — Find the right water, cooking time and yield for any type of rice.
• Roasting Time Calculator — Estimate roasting time and oven temperature by meat type and weight.
• Serving Size Calculator — Work out how much food to buy for a given number of guests.
• Slow Cooker Conversion Calculator — Convert oven or stovetop cooking times to slow cooker settings.
• Sourdough Starter Calculator — Work out feeding ratios and how much starter to build for a bake.
• Sous Vide Time Calculator — Estimate sous vide heating time from thickness and starting temperature.
• Yeast Conversion Calculator — Convert between fresh, active dry and instant yeast.

Agriculture

• Compost Ratio Calculator — Balance carbon and nitrogen in a compost mix to hit the ideal C:N ratio.
• Crop Yield Calculator — Convert yield per area into total production, bushels and revenue.
• Farm Gross Margin Calculator — Calculate gross margin per hectare from yield, price and variable costs.
• Fertilizer Calculator — Convert nutrient rates into product quantities for any fertiliser analysis.
• Germination Rate Calculator — Test seed viability and adjust the sowing rate for pure live seed.
• Grain Storage Calculator — Calculate the capacity of a bin or store in tonnes and bushels.
• Hay Bale Calculator — Work out how many bales a herd needs, or how many a field will yield.
• Irrigation Calculator — Calculate irrigation water volume, run time and crop water requirement.
• Lime Application Calculator — Calculate agricultural lime needed to raise soil pH.
• Livestock Feed Calculator — Calculate daily and seasonal feed requirements for a herd or flock.
• Livestock Water Calculator — Calculate daily water demand and storage needs for stock.
• Plant Spacing Calculator — Calculate plants per area from row and in-row spacing.
• Rainwater Harvesting Calculator — Estimate how much rainwater a roof or catchment can collect.
• Seed Rate Calculator — Work out sowing rate from target plant population, seed weight and germination.
• Spray Mix Calculator — Calculate product per tank, total product and number of tank loads.
• Stocking Rate Calculator — Work out grazing days, stocking rate and whether pasture will last.

Engineering

• Beam Deflection Calculator — Calculate maximum deflection, moment and stress for a loaded beam.
• Belt Length Calculator — Calculate belt length, wrap angle and speed ratio for a two-pulley drive.
• Bending Stress Calculator — Find bending stress from moment and section, and check it against yield.
• Bolt Torque Calculator — Calculate tightening torque and clamp load for a bolted joint.
• Column Buckling Calculator — Find the Euler critical buckling load and slenderness ratio for a column.
• Heat Transfer Calculator — Calculate conductive heat flow through a wall, and its R and U values.
• Hydraulic Cylinder Calculator — Calculate cylinder force, speed and flow demand from bore and pressure.
• Moment of Inertia Calculator — Calculate second moment of area, section modulus and radius of gyration.
• Pipe Flow Calculator — Convert between flow rate, velocity and pipe size using continuity.
• Pressure Drop Calculator — Calculate friction pressure loss along a pipe using Darcy–Weisbach.
• Pump Power Calculator — Calculate hydraulic, shaft and motor power for a pump duty.
• Reynolds Number Calculator — Determine whether flow is laminar or turbulent from the Reynolds number.
• Safety Factor Calculator — Calculate factor of safety, allowable stress or the load a design can take.
• Spring Rate Calculator — Calculate the rate, force and stress of a helical compression spring.
• Stress and Strain Calculator — Calculate axial stress, strain, elongation and Young’s modulus.
• Thermal Expansion Calculator — Calculate how much a part grows with temperature, and the stress if it cannot.