Appliance Running Cost Calculator

Compare the running cost of several appliances side by side.

Please note: For planning and educational use only. Electrical installation is governed by wiring regulations and is dangerous when done incorrectly. Always have work designed, installed and inspected by a qualified electrician.

What the Appliance Running Cost Calculator does

Running cost is power times hours times tariff. Comparing an existing appliance against a more efficient alternative shows whether the upgrade pays for itself, and how quickly.

Formula

kWh per year = (Watts ÷ 1,000) × Hours per day × 365
Cost per year = kWh × Rate
Payback = Purchase cost ÷ Annual saving

Inputs explained

Input	Unit	Required	Notes
Appliance power	W	Yes	Accepts more than 0.
Hours per day	number	Yes	Accepts 0 or more, up to 24.
Rate per kWh	selected currency	Yes	Accepts more than 0.
Alternative appliance power	W	Optional	Compare against a more efficient model. Accepts 0 or more.
Cost of the alternative	selected currency	Optional	Purchase price, for payback. Accepts 0 or more.
Currency	one of 10 options	Optional	—

How to use it

Choose Currency.
Enter Appliance power, Hours per day and Rate per kWh.
Optionally add Alternative appliance power and Cost of the alternative.
Select Calculate.

Worked example

A 2,000 W heater running 2 hours a day at $0.28/kWh.

Watts: 2000
Hours: 2
Rate: 0.28

2 kW × 2 h × 365 = 1,460 kWh a year, costing $408.80 — about $34.07 a month.

Frequently asked questions

Which appliances cost the most to run?

Anything that heats or cools: electric heaters, water heaters, tumble dryers and air conditioning. High wattage plus long hours is the expensive combination.

Method and sources

Method. Annual energy from rated power and daily hours, priced at the tariff entered.

Applies to. None — you supply the tariff

Assumptions

Usage is consistent through the year and the appliance draws its rated power while running.

Limitations

Thermostatically controlled appliances cycle, so rated power overstates average draw considerably.
Standby consumption is not included unless entered, and across many devices it is not negligible.
Seasonal appliances — heating, cooling — do not run evenly across a year, so an annualised figure from typical daily hours misleads.

Sources

The appliance energy label or datasheet, and your own tariff — Varies by manufacturer and supplier. Measured annual consumption where a label provides it, which is more reliable than rated power times hours.