How to use the Battery Percentage
The Formula
Percentage = (current charge ÷ full capacity) × 100. Use the same unit for both values—milliamp-hours (mAh) or amp-hours (Ah).
Practical Example
Devices estimate state-of-charge with voltage curves and usage history. This calculator gives a simple linear ratio useful for pack planning and quick checks.
About Battery Percentage
How battery percentage works
Percentage = (current charge ÷ full capacity) × 100. Use the same unit for both values—milliamp-hours (mAh) or amp-hours (Ah).
Why estimates differ from your phone
Devices estimate state-of-charge with voltage curves and usage history. This calculator gives a simple linear ratio useful for pack planning and quick checks.