Power Bank Charge Calculator
Calculate how many times a power bank can charge your device based on capacity and conversion efficiency.
Charge Estimate
Power bank charging is not 100% efficient due to voltage conversion and heat loss.
Usable Capacity = Power Bank mAh × Efficiency × (Bank Voltage / Device Voltage)
Typical efficiency: 80–90% for quality power banks.
Common device batteries:
| Device | Typical Battery |
|---|---|
| iPhone 15 | 3,349 mAh |
| Samsung Galaxy S24 | 4,000 mAh |
| iPad Air | 7,600 mAh |
| AirPods case | 300 mAh |
| Apple Watch | 300 mAh |
| Nintendo Switch | 4,310 mAh |
Power bank sizes:
- Small: 5,000 mAh (1–2 phone charges)
- Medium: 10,000 mAh (2–3 phone charges)
- Large: 20,000 mAh (4–6 phone charges)
- Travel max (airline limit): 27,000 mAh (100 Wh)