mAh to Wh Calculator
Convert mAh to Wh with the formula, a worked example and a table of typical values. Working shown step by step.
Try your own numbers
Estimate only. Not engineering or safety advice. Check the result against the applicable standard and the equipment data, and have a competent engineer review it before it is relied on. Terms of use.
Open in the calculator with these values
Formula
Worked example
| Input | Value |
|---|---|
| Battery capacity | 5,000 mAh |
| Nominal voltage | 3.7 V |
- Wh = mAh × V / 1000 = 5,000 mAh × 3.7 V / 1000 = 18.5 Wh
Typical values
| Battery capacity (mAh) | Energy (Wh) |
|---|---|
| 1,000 | 3.7 |
| 2,000 | 7.4 |
| 3,000 | 11.1 |
| 5,000 | 18.5 |
| 10,000 | 37 |
| 20,000 | 74 |
Other inputs are the same as in the worked example above.
Assumptions
- Nominal (mid-discharge) voltage, not the full-charge voltage
- Constant voltage over the discharge
Cells in series add voltage (3 Li-ion cells = 11.1 V) and keep the cell capacity; cells in parallel add capacity and keep the cell voltage. Use the pack voltage. Rated energy is not usable energy: depth of discharge, converter losses and temperature reduce it.
Frequently asked questions
How do I convert mAh to Wh?
Wh = mAh × V / 1000; mAh = Wh × 1000 / V. Worked example: Battery capacity 5,000 mAh, nominal voltage 3.7 V gives 18.5 Wh.
What do I need to enter?
Enter battery capacity, nominal voltage and energy. Leave blank the value you want to find, and the form solves for it. Change the unit of a value with its selector and the result stays the same.
Which voltage should I use?
Use the nominal voltage printed on the cell or pack, not the full-charge voltage. Cells in series add voltage, so use the pack voltage. The result is rated energy, not usable energy: depth of discharge, converter losses and temperature reduce it.
How accurate are the results?
Every figure comes from the same tested engine as the Elecmetric calculators and is meant for estimating. Check design values against the standard and the equipment data you work to.
Related
Next steps in a design: Joules to VoltskW to kWhEnergy Unit Converter
Opposite direction: Wh to mAh
Also see: Ah to Wh Wh to Ah Ah to kWh kWh to Ah
Formula guides: Battery Capacity ConverterBattery Formulas: Capacity and RuntimeBattery Pack Formulas: Series and Parallel
All 78 conversionsmAh to Wh and Wh to mAh in Elecmetric