Phone battery runtime estimator
Estimate runtime from battery capacity in mAh and average current draw in mA.
Estimate runtime from battery capacity in mAh and average current draw in mA.
Estimated result
Use the calculator
Enter capacity mAh, average draw mA. The calculation runs locally in this browser and returns estimated hours until empty.
Read the estimate carefully
Use the result as a comparison point for similar sessions, not as a hidden sensor reading or a hardware diagnosis.
- Real use changes with radios, screen brightness, temperature, and battery age.
- mAh divided by mA is a simplified steady-load estimate.