# How to convert watts to kWh

How to convert electric power in watts (W) to energy in kilowatt-hour (kWh).

You can calculate kilowatt-hour from watts and hours. You can't convert watt to kilowatt-hour unit since watt and kilowatt-hour unit represent different quantities.

### Watts to kilowatt-hour calculation formula

The energy E in kilowatt-hour (kWh) is equal to the power P in watts (W), times the time period t in hours (hr) divided by 1000:

*E*_{(kWh)} = *P*_{(W)}* *×* t*_{(hr)}
/ 1000

So

kilowatt-hour = watt × hour / 1000

or

kWh = W × hr / 1000

#### Example

What is the energy consumption in watt-hour when the power consumption is 5000 watts for time duration of 3 hours?

*E* = 5000W × 3h / 1000 = 15 kWh