Calculator Inputs and Outputs
Inputs
- Power bank rated capacity (mAh) — example: 20000
- Power bank cell voltage (V) — example: 3.7
- Phone battery capacity (mAh) — example: 5000
- Phone battery voltage (V) — example: 3.85
- Overall efficiency (%) — example: 75
Results
- Estimated full phone charges (charges)
- Usable power-bank energy (Wh)
- Phone battery energy (Wh)
Formula used
Charges = usable power-bank watt-hours ÷ phone battery watt-hours.
How to Use the Power Bank Phone Charge Calculator
Enter the requested values, confirm the units and assumptions, then select Calculate Power Bank Phone Charge. The default inputs provide a complete working example.
Formula
Charges = usable power-bank watt-hours ÷ phone battery watt-hours.
Understanding the Results
The primary answer appears first. Supporting outputs provide related quantities, conversions, timing, costs, ratios, or intermediate values. The calculator keeps extra precision internally before display rounding.
Accuracy Tips
- Use measured values and consistent units.
- Review rates, timing, allowances, efficiency, and category-specific assumptions.
- Recalculate whenever a project condition changes.
Important Note
This calculator is an informational planning tool. Confirm critical financial, medical, construction, scientific, tax, legal, or safety decisions with an appropriately qualified professional.
Calculation Standards
This tool uses documented formulas and high-precision internal values. Displayed results may be rounded for readability. Review the assumptions and verify important decisions with a qualified professional.
Read our calculation methodology