Electricity Cost Calculator

How to calculate electricity cost

Divide the power in watts by 1,000 to convert it to kilowatts, then multiply by hours and price per kilowatt-hour. A 1,000 watt device for three hours at 0.25 per kWh costs 0.75.

Formula

watts ÷ 1000 × hours × price

Worked example

Power (watts)

1,000

Hours used

3

Price per kWh

0.25

Applying the formula to these values gives 0.75 .

What should I check?

Use your own tariff. This excludes standing charges, and appliances that cycle on and off may use less than their rated power over the whole period.

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