Watt-hours to Amp-hours Calculator
Convert watt-hours to amp-hours at any battery voltage for solar and off-grid sizing with this free calculator, right in your browser.
Enter Values
Minimum 0
Minimum 0
How to use this calculator
- Enter the watt-hours and the voltage.
- Read the amp-hours.
How it works
Amp-hours = watt-hours ÷ voltage.
Worked example
500 Wh at 12 V. ≈ 41.7 Ah.
Common mistakes
- Using the wrong battery voltage (12 V vs 24 V vs 48 V).
- Forgetting usable capacity is less than rated (depth of discharge).
Frequently asked questions
How do I convert Wh to Ah?
Ah = Wh ÷ battery voltage. A 600 Wh battery at 12 V is 50 Ah.
Why does voltage matter for amp-hours?
Amp-hours describe charge at a given voltage, so the same energy is fewer amp-hours at higher voltage — which is why 48 V systems use thinner cabling.
How do I go back from Ah to Wh?
Multiply amp-hours by voltage: Wh = Ah × V.
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Cite this tool
Zerdly. (2026). Watt-hours to Amp-hours Calculator. Retrieved from https://www.zerdly.com/tools/watt-hours-to-amp-hours-calculator/
Tip: Enter any known values to calculate the remaining results.
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