Free Online Tool
Battery Life Calculator
Estimate runtime using battery capacity in mAh and load current in mA.
The result will appear here.
How to Use
- Enter battery capacity in mAh.
- Enter current draw in mA.
- Review estimated runtime in hours and days.
Examples
- Estimate runtime for 2000mAh and 100mA
- Check expected operating days for a low-power device
Calculation and Conversion Notes
Estimated runtime is calculated as `battery capacity(mAh) / current draw(mA)`. Actual runtime can vary with battery discharge characteristics, temperature, circuit efficiency, and load changes.
FAQ
Does Battery Life Calculator save my input?
No. Your input is not stored on a server. Supported actions run in your browser.
Can I use it on mobile?
Yes. The pages are responsive and work on desktop and mobile browsers.
Can I rely on the result?
Use the result as a quick reference. Important work should be checked separately.