Battery capacity is often listed in watt-hours (Wh), but devices and chargers typically use milliamp-hours (mAh) — the Wh to mAh Calculator converts between the two so you can compare batteries directly. Enter your battery's energy in watt-hours and its voltage (V) to get the equivalent capacity in milliamp-hours (mAh).
Milliamp-Hours
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To convert Wh to mAh, use the formula: mAh = (Wh × 1000) ÷ Voltage. Multiply watt-hours by 1000 and divide by the voltage in volts.
Wh (watt-hours) measures energy capacity, while mAh (milliamp-hours) measures charge capacity. Wh tells you how much energy a battery can store, while mAh tells you how much current it can deliver over time.
Voltage is essential because the relationship between energy (Wh) and charge (mAh) depends on the electrical potential. The same energy at different voltages will result in different charge capacities.
Yes, you can convert mAh to Wh using the formula: Wh = (mAh × Voltage) ÷ 1000. You still need to know the voltage for this conversion.
Common battery voltages: AA/AAA alkaline (1.5V), Lithium-ion phone batteries (3.7V), car batteries (12V), and laptop batteries (10.8V to 14.8V). Check your battery label for the exact voltage.
Yes, this calculator works for all battery types as long as you use the correct voltage. The conversion formula is universal and applies to lithium-ion, alkaline, lead-acid, and other battery chemistries.