Convert watt-hours to milliamp-hours at any voltage. Reverse of mAh to Wh — useful for power banks and airline battery limits.
| Input | Result |
|---|---|
| 74 Wh at 3.7 V | 20,000 mAh |
| 100 Wh at 3.7 V | 27,027 mAh |
| 100 Wh at 5 V | 20,000 mAh |
Divide watt-hours by voltage and multiply by 1000: mAh = Wh × 1000 ÷ V. 74 Wh at 3.7 V is 20,000 mAh; the same 74 Wh at 12 V is only 6,167 mAh.
They are measured at the 3.7 V cell voltage, while USB output is 5 V. A '20,000 mAh' bank stores 74 Wh — at 5 V that is only about 14,800 mAh of output before conversion losses.
No — mAh is charge. Energy (Wh) = charge (Ah) × voltage. Comparing mAh across different voltages is meaningless; convert to Wh first.