Watts to kWh calculator

Watts measure how fast energy is used; kilowatt-hours measure how much. Enter the wattage and running time.

VC-15 energyW × h ÷ 1000
W
h
¢/kWh
Energy per day0.5kWh
Per month 15 kWhPer year 183 kWhCost/month $2.73

Watts vs kilowatt-hours

A watt is a rate: how fast a device uses energy right now. A kilowatt-hour is an amount: 1,000 watts running for one hour. Your utility bills in kWh.

kWh = watts × hours ÷ 1000
Watts1 h8 h24 h30 days × 8 h
10 W0.010.080.242.4
60 W0.060.481.4414.4
100 W0.10.82.424
500 W0.5412120
1,000 W1824240
1,500 W1.51236360
3,000 W32472720

Energy in kWh.

Questions people ask

How do I convert watts to kWh?

kWh = watts × hours ÷ 1000. A 100 W TV on 5 hours a day uses 0.5 kWh per day, about 15 kWh a month.

How many kWh does a 1500 W heater use?

1.5 kWh for every hour it runs at full power. Thermostat cycling usually makes the real figure lower.