Wh to mAh Calculator
Enter energy and nominal battery voltage to calculate rated charge capacity.
Formula
mAh = Wh × 1,000 ÷ V; Ah = Wh ÷ V.
Battery energy: 37 Wh · Nominal battery voltage: 3.7 V · Charge capacity ≈ (37 Wh × 3,600 J/Wh)÷(3.6×(3.7 V)) · Charge in amp-hours ≈ (10,000)÷1000
How to use
- Enter the battery energy.
- Enter its nominal voltage, not a charger output voltage.
- Read the equivalent mAh and Ah.
Examples
- 37 Wh at 3.7 V gives 10,000 mAh.
Frequently asked questions
Why is voltage required?
Wh measures energy; mAh measures charge. The conversion depends on voltage.
Does this predict usable capacity?
No. Nominal voltage gives a rating estimate; discharge conditions and conversion losses affect delivery.
Which voltage should I use?
Use the nominal voltage of the same cell or pack whose Wh rating you entered.
Sources
Updated: