Electricity Cost Calculator

Enter the device power, how many hours it runs and your electricity price to see kilowatt-hours used and what that session costs.

How it works

Energy in kilowatt-hours is power in kilowatts times hours. Watts are converted by dividing by 1000, so a 1000 W heater for 2 hours uses 2 kWh. Cost is kWh × the price you pay per kWh. Hours here is the duration of this use, not a billing month — multiply the cost by how often you run it if you want a longer period, or use the appliance calculator for hours/day and days/month.

Formula

kW = watts ÷ 1000 (when power is in W)
kWh = kW × hours
Cost = kWh × price per kWh

Worked examples

1000 W, 2 h, 0.20 / kWh → 2 kWh, cost 0.40
1.5 kW, 4 h, 0.30 / kWh → 6 kWh, cost 1.80

Useful notes

This is not your bill. Tariffs, standing charges and time-of-use rates are not modelled.
For a named appliance with daily hours, use Appliance Energy Cost.

FAQ

How do I calculate electricity cost from watts?: Convert watts to kW (÷ 1000), multiply by hours for kWh, then multiply by your price per kWh.
Should I enter watts or kilowatts?: Either. Nameplates often show watts; EV chargers and larger loads are often in kW. Pick the matching unit.
Does this include standing charges?: No. It only multiplies energy by the unit price you enter.

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