Power-bank capacity planner
Estimate usable watt-hours and rough device recharges. This is a planning estimate, not a safety or aviation approval.
Enter values, then estimate.
Why mAh alone is misleading
Power-bank capacity is commonly stated at the internal cell voltage. The device is charged at another voltage after conversion, and some energy becomes heat. Watt-hours provide a more comparable energy measure. Check the printed watt-hour rating and current airline rules when flying.