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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 WhConverted capacity: 0.37 Wh

Wh = 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.
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WattRunTime.com

WattRunTime battery capacity conversion

Converted capacity0.37 Wh
ModemAh to Wh
Watt-hours0.37 Wh
Voltage3.7 V
Result0.37 Wh

WattRunTime battery capacity conversion

  • WattRunTime battery capacity conversion
  • Mode: mAh to Wh
  • Input: 100 mAh
  • Voltage: 3.7 V
  • Result: 0.37 Wh
  • Watt-hours: 0.37 Wh
  • Travel note: 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.
  • Use the voltage printed on the battery label when available. mAh without voltage cannot be compared fairly.

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.

Use mAh to Wh before runtime or flight checks

This direction turns a power-bank or battery-pack mAh label into watt-hours, which is the unit runtime and airline limits actually need.

Formula focus

Wh = mAh x V / 1000. A 30,000 mAh pack at 3.7 V is about 111 Wh before any output losses.

Best use case

Use this when the label lists mAh first and you need a cautious Wh number for travel, sizing, or runtime planning.

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