Capital Gains Tax Calculator

Calculate tax on an asset sale, with separate short-term and long-term rates.

Please note: A general estimate, not tax advice. Rates, bands, allowances and rules differ by country and change frequently. Enter the figures that apply to you and confirm with a qualified tax professional or your tax authority.

What the Capital Gains Tax Calculator does

Capital gains tax applies to the profit from selling an asset, not the sale price. The gain is proceeds minus cost basis, where the basis includes purchase price plus acquisition and disposal costs. Holding period usually determines the rate.

Formula

Cost basis = Purchase price + Buying and selling costs
Gain = Sale price − Cost basis
Taxable gain = max(0, Gain − Losses − Allowance)
Tax = Taxable gain × Rate

Inputs explained

Input	Unit	Required	Notes
Sale price	selected currency	Yes	Accepts more than 0.
Purchase price	selected currency	Yes	Accepts more than 0.
Buying and selling costs	selected currency	Optional	Commission, legal fees, improvements. Accepts 0 or more.
Holding period	one of 2 options	Yes	—
Long-term rate	%	In some modes	Shown Holding period is Long-term (held beyond the threshold).
Short-term rate	%	In some modes	Usually your marginal income tax rate. Shown Holding period is Short-term (held under the threshold).
Annual tax-free allowance	selected currency	Optional	Accepts 0 or more.
Losses to offset	selected currency	Optional	Capital losses from other disposals. Accepts 0 or more.
Currency	one of 10 options	Optional	—

How to use it

Choose Holding period and Currency.
Enter Sale price and Purchase price.
Fill in the remaining inputs the form shows for your choice.
Optionally add Buying and selling costs, Annual tax-free allowance and Losses to offset.
Select Calculate.

Worked example

Bought at $40,000, sold at $75,000, $2,500 of costs, long-term at 15%, $3,000 allowance.

Sale: 75000
Purchase: 40000
Costs: 2500
Rate: 15
Allowance: 3000

Basis $42,500, gain $32,500, taxable $29,500, tax $4,425 — net gain $28,075.

Frequently asked questions

What is the difference between short-term and long-term?

Assets held beyond a threshold, commonly a year, usually qualify for a reduced rate. Short-term gains are often taxed as ordinary income at your marginal rate.

Can I offset losses against gains?

Generally yes, and unused losses often carry forward to future years. Watch for wash-sale rules that disallow a loss if you repurchase the same asset too quickly.

Method and sources

Method. Gain is the sale price less the cost basis, where the basis includes acquisition and disposal costs; losses and any allowance entered are applied before the rate.

Assumptions

Holding period decides which rate applies, and the reader selects that rate — the calculator holds no threshold for what counts as long-term.
Losses entered are of a kind that can be set against this gain, which real systems restrict.

Limitations

Which costs may be added to basis, how losses carry, and whether any allowance exists differ by jurisdiction and by asset class.
Rules that materially change the answer are not modelled: reliefs on a main residence, wash-sale restrictions, indexation, and different treatment for collectables or property.
No rate table ships with this calculator: you supply the rates, so the result follows whichever jurisdiction and year you enter. That means it can never go silently out of date — but it also cannot warn you if the figures you entered are.

Sources

Your own tax authority's published guidance for the relevant year — Varies by jurisdiction. The rates, the holding-period threshold, allowable basis costs and any exemption.