# Convert mAh to Wh and Wh to mAh - Conversion Calculator

Conversion between different units, especially when different unit prefixes are used is an ideal situation for making - mistakes.

If You need to convert mAh to Wh and Wh to mAh, feel free to use our unit conversion calculator. ## Little Bit of Math and Physics

In order to convert mAh (milli Ampere-hours - battery capacity) to Wh (Watt-hours - energy, for example, stored in the batteries), we need to use this formula:

E (Wh) = U (V) * C (Ah)

where U (V) is a voltage of a battery or some other electric source.

If the battery capacity (C) is given in mAh, we must use these formulas:

C (mAh) = C (Ah) * 1000 → C (Ah) = C (mAh) / 1000

Thus:

E (Wh) = U (V) * C (Ah) = U (V) * C (mAh) / 1000

E (mWh) = U (V) * C (mAh)

For more about unit prefixes, feel free to check our SI Unit Prefixes: How Many Watts in Kilowatt? article.

For example:

LR44 battery is an 11.6 x 5.4 mm alkaline battery with an average voltage of 1.3 volts and an average capacity of ~120 mAh - this battery is thus able to store:

E (Wh) = U (V) * C (mAh) / 1000 = 1.3 V * 120 mAh / 1000 = 0.156 Wh = 156 mWh

SR44 battery is an 11.6 x 5.4 mm silver-oxide battery with an average voltage of 1.4 volts and an average capacity of ~200 mAh - this battery is thus able to store:

E (Wh) = U (V) * C (mAh) / 1000 = 1.4 V * 200 mAh / 1000 = 0.28 Wh = 280 mWh

As one can see, thanks to the larger average voltage and capacity, the silver-oxide SR44 battery is able to provide almost double the energy of the alkaline LR44 battery.

PR44 (Blue Tab) battery is an 11.6 x 5.4 mm zinc-air battery with an average voltage of 1.3 volts and an average capacity of ~650 mAh - this battery is thus able to store:

E (Wh) = U (V) * C (mAh) / 1000 = 1.3 V * 650 mAh / 1000 = 0.845 Wh = 845 mWh

Although zinc-air batteries have somewhat smaller voltage than silver-oxide batteries, thanks to their much larger capacity, they can store ~3x more energy than silver-oxide batteries and ~5x more energy than alkaline batteries.

But, zinc-air batteries use wet/moist electrolyte exposed to air and they dry out after several weeks, regardless if they are used or not. Thus, their use is limited - they are used as excellent hearing aid batteries.

## mAh to Wh and Wh to mAh Conversion Calculators

In order to convert mAh to Wh and Wh to mAh, feel free to use these conversion calculators - write the values that You have and click 'Calculate' to convert them:

 MilliAmp-Hours (mAh) to Watt-Hours (Wh) MilliAmp-Hours (mAh): Volts (U): Watt-Hours (Wh): MilliWatt-Hours (mWh): Watt-Hours (Wh) to MilliAmp-Hours (mAh) Watt-Hours (Wh): Volts: MilliAmp-Hours (mAh): Amp-Hours (mAh):

Long Story Short: If You want to convert Amp-hours or milli-Amp-hours to Watt-hours or milli-Amp-hours, use our conversion calculator and/or these formulas:

E (Wh) = U (V) * C (Ah) = U (V) * C (mAh) / 1000

E (mWh) = U (V) * C (mAh)

And be careful about unit prefixes, of course.