mAh to Wh Calculator
Estimate nominal battery energy from charge capacity and nominal voltage.
Formula
Wh = mAh × V/1000 = Ah × V.
Charge capacity: 2,000 mA·h · Nominal voltage: 3.7 V · Nominal energy ≈ (2,000 mA·h × 3.6 C/mA·h)×(3.7 V)÷3600
How to use
- Enter battery capacity in mAh or Ah.
- Enter the nominal voltage associated with that capacity.
- Read nominal energy in Wh.
Examples
- 2000 mAh at 3.7 V is nominally 7.4 Wh.
Frequently asked questions
Can mAh alone give Wh?
No. The battery voltage is required.
Which power-bank voltage do I use?
Use the cell or pack voltage for the stated capacity, not an unrelated USB output voltage.
Is usable energy identical?
No. Discharge conditions, changing voltage and conversion losses affect delivered energy.
Sources
Updated: