Battery capacity calculator

Alternative name: Amp-hours to Watt-hours, Watt-hours in battery calculator

Use this battery capacity calculator to figure out how many watt-hours or kilowatt hours you have available based on your battery voltage and amp-hours. This calculator works for any type of battery, including lithium batteries, alkaline batteries, Carbon Zinc batteries, lead-acid batteries, and so on.


Battery capacity: 1260 watt-hours
Battery capacity: 1.26 kilowatt hours

This battery capacity calculator considers a constant discharge current. The resulting watt-hour is an estimate of how much energy a battery has.

Our calculations

At Calculatorian, we are keen to share our knowledge, be transparent and open to feedback. Here are the calculations used to create this calculator. If you find an error or deficiency, contact us and we'll fix it in an instant!

Battery capacity was calculated like this:

Battery capacity was calculated like this:

Variables used in this formula

volt = Volt
ah = Amp-hours