Amp-hours to Watt-hours Converter
Convert battery charge capacity in amp-hours (Ah) to energy capacity in watt-hours (Wh). You must know the nominal voltage of the battery.
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Ampere-hour ↔ Watt-hour
Ah
Wh
Calculation Formula
100 Ah × 12 V = 1,200 Wh
Worked Example
Convert 100 Ah to Wh at 12V:
100 Ah × 12 V = 1,200 Wh
Ampere-hour to Watt-hour Table
Note: Do not compare Ah ratings of batteries with different voltages. Always convert to Wh or kWh to compare total energy capacity.
| Ah | Wh (12V) | Wh (24V) | Wh (48V) |
|---|---|---|---|
| 10 Ah | 120 Wh | 240 Wh | 480 Wh |
| 50 Ah | 600 Wh | 1,200 Wh | 2,400 Wh |
| 100 Ah | 1,200 Wh | 2,400 Wh | 4,800 Wh |
| 150 Ah | 1,800 Wh | 3,600 Wh | 7,200 Wh |
| 200 Ah | 2,400 Wh | 4,800 Wh | 9,600 Wh |
| 300 Ah | 3,600 Wh | 7,200 Wh | 14,400 Wh |
Understanding the Conversion
Amp-hours measure electric charge capacity, not true energy. To find how much actual energy a battery holds (watt-hours), you must multiply its amp-hour rating by its voltage.
Frequently Asked Questions
Why is battery voltage required?
Amp-hours only measure electric charge (current over time). Energy (watt-hours) depends on both the charge and the electrical potential (voltage) pushing that charge.
Is Ah the same as Wh?
No. Ah is charge capacity, Wh is energy capacity. 100Ah at 12V is 1200Wh, but 100Ah at 48V is 4800Wh.
Size your backup power system.
Use these converted ratings to determine exactly what size generator or battery bank you need.