Home Tech Vault practical guide
How do I convert watts to kWh?
Divide watts by 1,000 to get kilowatts, then multiply by hours of operation. A 1,000-watt device running for one hour uses 1 kWh if its power draw stays constant.
By Home Tech Vault · Reviewed October 21, 2026
Keep power and energy separate
Watts describe a rate of energy use; kWh describes energy consumed over time. You need both power and duration to estimate consumption.
Account for cycling
For equipment that cycles or changes power levels, use average watts or equivalent full-power operating hours. A label’s maximum rating is not necessarily the daily average.
Add your electricity price
Once you have kWh, multiply by the price per kWh. Use the running-cost calculator to compare several operating-time assumptions.
Try it with your own numbers
A 1,000-watt appliance used one hour daily at $0.15/kWh costs $4.50 over 30 days and about $54.75 over 365 days.
Open the free appliance running cost calculator →
Cycling appliances do not continuously draw their rated maximum power. Use measured average consumption or the EnergyGuide label when available. Fixed utility fees are excluded.