Ah to Wh Calculator
Convert between battery capacity (Ah) and stored energy (Wh) at any system voltage. 12V, 24V, 48V — for camper, boat, RV, and off-grid LiFePO4, AGM, and lead-acid banks.
Ah to Wh Calculator
Result
Energy in Wh equals capacity in Ah multiplied by battery voltage. 1000 Wh equals 1 kWh.
Need a complete wiring diagram?
VoltPlan designs full electrical systems for campers, boats, and off-grid setups with automatic wire sizing, fuse placement, and battery configurations.
Design Your SystemCommon Battery Capacities (Ah → Wh)
Common single-battery sizes converted to stored watt-hours at the typical DC system voltages. Multiply by the number of batteries in parallel to size a complete bank.
| Capacity | @ 12V | @ 24V | @ 48V |
|---|---|---|---|
| 50 Ah | 600 Wh | 1200 Wh (1.2 kWh) | 2400 Wh (2.4 kWh) |
| 75 Ah | 900 Wh | 1800 Wh (1.8 kWh) | 3600 Wh (3.6 kWh) |
| 100 Ah | 1200 Wh (1.2 kWh) | 2400 Wh (2.4 kWh) | 4800 Wh (4.8 kWh) |
| 150 Ah | 1800 Wh (1.8 kWh) | 3600 Wh (3.6 kWh) | 7200 Wh (7.2 kWh) |
| 200 Ah | 2400 Wh (2.4 kWh) | 4800 Wh (4.8 kWh) | 9600 Wh (9.6 kWh) |
| 230 Ah | 2760 Wh (2.8 kWh) | 5520 Wh (5.5 kWh) | 11040 Wh (11.0 kWh) |
| 280 Ah | 3360 Wh (3.4 kWh) | 6720 Wh (6.7 kWh) | 13440 Wh (13.4 kWh) |
| 300 Ah | 3600 Wh (3.6 kWh) | 7200 Wh (7.2 kWh) | 14400 Wh (14.4 kWh) |
| 400 Ah | 4800 Wh (4.8 kWh) | 9600 Wh (9.6 kWh) | 19200 Wh (19.2 kWh) |
Frequently Asked Questions
How do I convert Ah to Wh?
Multiply amp-hours by battery voltage. 100Ah × 12V = 1200Wh. 100Ah × 24V = 2400Wh. Higher voltage stores more energy at the same Ah.
How do I convert Wh to Ah?
Divide watt-hours by battery voltage. 1200Wh ÷ 12V = 100Ah. 1200Wh ÷ 24V = 50Ah.
Why does voltage matter for battery comparison?
Energy (Wh) is what powers loads. Two batteries with the same Ah at different voltages store different amounts of energy. Always compare in Wh or kWh for a fair comparison.
How big a bank do I need for a camper?
Typical camper: 1500–2500 Wh per day. With 80% DoD on LiFePO4 and one day autonomy, that is roughly 200–300 Ah at 12V.
Does temperature affect Ah and Wh?
Yes. Cold temperatures reduce usable capacity. At 0°C expect ~85% of rated Ah; at -10°C around 70% for most chemistries. The calculator returns nameplate values; derate for your operating temperature.
What is the Wh of a 100Ah LiFePO4?
About 1280Wh at the LiFePO4 nominal voltage of 12.8V. Round to 1200Wh at the system nominal of 12V. Set the voltage in the calculator to match what you want to compare against.
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