Amp-hour to Watt-hour Calculator
Enter capacity in amp-hours and nominal voltage to estimate stored energy in watt-hours.
A QUICK WALKTHROUGH
How to use this tool
- Enter amp-hours and voltage.
- Calculate watt-hours with Wh = Ah × V.
- Treat the result as nominal energy, not guaranteed usable output.
Nominal energy
Watt-hours equal amp-hours multiplied by volts. Real usable energy can be lower because of discharge limits, age, temperature, losses, and rating conditions.
Input boundary
Use finite positive Ah and voltage values. Keep the voltage consistent with the battery rating.
Local calculation
Calculation happens in your browser without uploading or storing your values.
GOOD TO KNOW
Common questions
What voltage should I use?
Use the battery’s stated nominal voltage, not a momentary charging voltage.
Does Wh equal runtime?
No. Runtime also depends on load, conversion losses, cutoff settings, and battery condition.
Can I enter decimals?
Yes. Finite positive decimal capacity and voltage values are supported.