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kWh Calculator

Calculate kilowatt hours (kWh) from watts and hours. Find energy consumption and electricity cost for any appliance.

Power (Watts)

Watts

Hours Per Day — 8h

Electricity Rate ($/kWh) — $0.13

US average: $0.13/kWh · UK: ~$0.28 · Australia: ~$0.25

Daily kWh12 kWh

Monthly kWh360 kWh

Cost Per Day$1.56

Cost Per Month$46.80

Cost Per Year$569.40

How to Use the kWh Calculator

Enter your values above for an instant result. This tool uses verified formulas and is optimised for users in USA, Canada, UK, Australia. All calculations happen in your browser — your data is never sent to our servers.

Frequently Asked Questions

How do you calculate kWh?

kWh = Watts × Hours / 1000. A 100W light bulb running 10 hours = 1 kWh. At $0.13/kWh, that costs 13 cents.