Watts to cost

Electricity Cost Calculator

Turn appliance watts and usage hours into kWh and a clear electricity-cost estimate.

Live calculator

Calculate your actual running cost

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Find watts on the appliance label. Your bill shows the price per kWh.

Estimated monthly cost$91.00303.3 kWh per month
Per hour$0.60
Per day$3.00
Per year$1092.00

Running this electric heater for 5 hours a day, 7 days a week uses about 303.3 kWh each month.

The formula

How electricity cost is calculated

Divide watts by 1,000 to convert power to kilowatts. Multiply kilowatts by the hours used to get kWh, then multiply kWh by your unit price. A 1,000 W appliance used for two hours consumes 2 kWh. At $0.30 per kWh, it costs $0.60.

Use your actual unit rate

Your electricity bill normally lists a unit rate per kWh. Fixed service or standing charges should not be added to an individual appliance calculation because you pay them regardless of whether that appliance is running.