watt hours to amp hours calculator

Watt Hours to Amp Hours Calculator

RV, solar, and battery systems often use Ah, but portable station specs use Wh. Convert between them with voltage visible.

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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

27.03 Ah

Ah = Wh / volts

Watt-hours100 Wh
Amp-hours27.03 Ah
Milliamp-hours27,027 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

Ah = Wh / V. For example, 1,200 Wh at 12 V is 100 Ah before inverter and battery-management losses.