mah to wh calculator
mAh to Wh Calculator
mAh is not enough by itself. Add voltage to convert a power bank label into watt-hours for runtime and travel planning.
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Voltage presets
Use the voltage printed on the battery label when available. mAh without voltage cannot be compared fairly.
Converted capacity
0.37 WhWh = mAh x volts / 1000
Watt-hours0.37 Wh
Amp-hours0.1 Ah
Milliamp-hours100 mAh
Voltage3.7 V
Travel check: At or below 100 Wh, lithium-ion spare batteries are within the standard FAA PackSafe size limit, but airline, route, and damage-protection rules still apply. Check the FAA PackSafe lithium battery page and your airline before flying with spare batteries or power banks. Reviewed 2026-06.
Formula
Wh = mAh x V / 1000. For example, 30,000 mAh at 3.7 V is about 111 Wh.