Wh to mAh Converter — Watt-Hours to Battery Capacity
CalculatorA Wh to mAh converter multiplies energy (Wh) by 1000 and divides by voltage (V) to get battery capacity in milliampere-hours.
What is it
Use this when a battery is labeled in Wh — as laptop batteries are — and you want the mAh figure familiar from phones and power banks. The same Wh yields fewer mAh at a higher voltage, so the nominal battery voltage is required. For example a 57Wh laptop battery at 11.1V is about 5,135mAh, but converted at the 3.7V cell basis it corresponds to about 15,405mAh.
How to use
- 1Enter the energy in Wh.
- 2Enter the nominal battery voltage (V).
- 3Press calculate to get the capacity in mAh.
Reference
| Energy | Voltage | Capacity |
|---|---|---|
| 37Wh | 3.7V | 10,000mAh |
| 57Wh | 11.1V | 5,135mAh |
| 100Wh | 3.7V | 27,027mAh |
Sources & standards
FAQ
How many mAh is 100Wh?
It depends on voltage: at 3.7V, 100 × 1000 / 3.7 ≈ 27,027mAh; for an 11.1V laptop battery it is about 9,009mAh.
How do I compare a laptop battery in Wh with a power bank in mAh?
Power bank ratings use the 3.7V cell basis, so divide the laptop battery Wh by 3.7 to compare on the same basis.
Is Wh to mAh input sent to a server?
No. This calculator runs in your browser and does not send input to a server.