Electricity Cost Calculator
Cost to run appliances.
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Energy
Watts to kWh Calculator
Convert watts and run time to kilowatt-hours of energy used.
Energy used
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Kilowatt-hours.
| Watt-hours | — |
|---|---|
| kWh | — |
| Cost at $0.17 | — |
| Formula | — |
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Enter your figures above to see the step-by-step working.
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How the Watts to kWh Calculator Works
Energy is power multiplied by time. Run a device of a given wattage for a number of hours and it uses watt-hours; divide by 1,000 to get kilowatt-hours (kWh), the unit on your electricity bill. A 1,500 W heater running 3 hours uses 4.5 kWh. This calculator also estimates the cost at a typical rate.
It’s the bridge between an appliance’s power rating (watts, on its label) and what it actually consumes and costs over time.
kWh = watts × hours ÷ 1000
Frequently Asked Questions
How do I convert watts to kWh?
Multiply the watts by the hours run, then divide by 1,000. A 1,500 W device for 3 hours is 4.5 kWh.
What is the difference between watts and kWh?
Watts measure power (rate of use); kWh measure energy (amount used over time). kWh is watts times hours.
How much does 1 kWh cost?
It depends on your rate — commonly around 15–20 cents in the US. Check the per-kWh price on your bill.
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