Formula
kWh = watts × hours per day × days / 1000; cost = kWh × price per kWh
Worked example
A 1,500 W load operating 4 hours daily for 30 days consumes 1,500 × 4 × 30 / 1,000 = 180 kWh. At $0.25/kWh, the energy charge is $45.
Electricity Cost Calculator: Watts to kWh and Price
Convert power and operating time into energy consumption and an estimated electricity cost.
Open interactive calculator →Important limitations
The calculation assumes constant power. Real electricity bills may also include fixed charges, demand charges, taxes and time-varying tariffs. Enter a rate in the same currency you want the result displayed in.
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Educational approximation only. Verify results and applicable standards before electrical installation work.