Power Bank Charges Calculator
How many times a power bank can charge your phone.
mAh
mAh
%
How it works
Power banks list capacity at the cell voltage (3.7 V) but deliver power at 5 V or more, so only 60–80% of the rating reaches your phone. Charges = rating × efficiency ÷ phone battery capacity. A lower efficiency figure is safer for cheap power banks. Example: with the default values, full phone charges comes to 3.1.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.