# How to convert mAh to Wh

How to convert milliamp-hour (mAh) to watt-hour (Wh).

### milliamper-hour to watt-hour calculation

The energy *E*_{(Wh)} in watt-hours is equal to the
electric charge *Q*_{(mAh) }in milliampere-hour times the
voltage * V*_{(V) }in volts (V) divided by 1000:

*E*_{(Wh)} = *Q*_{(mAh)}*
× V*_{(V)}* */* *1000

So watt-hour is equal to milliamp-hour times volts divided by 1000:

watt-hours = milliampere-hours* × *volts / 1000

or

Wh = mAh* × *V / 1000

#### Example

Find the energy in watt-hours when the electric charge is 300 milliampere-hour and the voltage is 5 volts.

The energy *E* is equal to 300 milliamp-hour times 5 volts divided by 1000:

*E* = 300mAh × 5V / 1000 = 1.5Wh