Energy converter

mAh to Joules Converter

Calculate battery capacity energy in joules using milliamp-hours (mAh) and voltage.

How mAh to Joules works

Milliamp-hours (mAh) measure electric charge capacity, not actual energy. To find total energy in joules, you must multiply the charge capacity (mAh) by the electrical potential (nominal voltage).

First, convert mAh to watt-hours: Wh = (mAh × V) ÷ 1,000. Then convert watt-hours to joules: Joules = Wh × 3,600. Combining these gives the direct formula: J = mAh × V × 3.6.

Formula

1Wh = mAh × V ÷ 1,000

2J = Wh × 3,600

Nominal voltage (V) depends on the battery chemistry.

mAh to Joules conversion table

Reference Table6 rows

Common battery capacities converted to joules (assuming 3.7V nominal voltage).
Capacity (mAh)↕	Energy (Wh) at 3.7V↕	Energy (Joules) at 3.7V↕
1,000 mAh	3.7 Wh	13,320 J
2,000 mAh	7.4 Wh	26,640 J
3,000 mAh	11.1 Wh	39,960 J
5,000 mAh	18.5 Wh	66,600 J
10,000 mAh	37 Wh	133,200 J
20,000 mAh	74 Wh	266,400 J

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FAQ: mAh to Joules

How do you convert mAh to joules?

Multiply the battery capacity in milliamp-hours (mAh) by the battery nominal voltage (V), and then multiply that result by 3.6. Formula: Joules = mAh × Volts × 3.6.

Why do you need voltage to calculate energy from mAh?

Milliamp-hours measure electric charge capacity—the total number of electrons the battery holds. To know the energy (work) those electrons can perform, you need the pressure (voltage) pushing them.

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