Hardware tool
UPS Runtime Calculator
Estimate backup runtime from battery capacity, voltage, load, efficiency, and safe discharge.
Runs in your browserResult
- Nominal battery energy
- 216 Wh
- Usable AC energy
- 119.3 Wh
- Estimated runtime
- 39.8 minutes
- Estimated runtime
- 0.66 hours
- Load at battery
- 211.8 W
Real UPS runtime is nonlinear and depends on battery age, discharge rate, temperature, inverter overhead, topology, and manufacturer cutoffs.
How to use this UPS runtime calculator
- Enter the rated capacity or power, expected load, losses, and safety allowance from the equipment labels or plan.
- Review the calculated totals, units, and assumptions. Check the inputs and units before relying on the result.
- Change one input at a time to compare another case, then copy or save the result you plan to use.
About this UPS runtime calculator
UPS Runtime Calculator helps you estimate backup runtime from battery capacity, voltage, load, efficiency, and safe discharge. The input and result appear together for easy comparison.
You can also use it to compare results after changing one input.
Example
Enter battery voltage and capacity with a 300-watt load, then account for usable capacity and efficiency for a more realistic runtime estimate.
Common uses
- → estimate backup runtime from battery capacity, voltage, load, efficiency, and safe discharge
- → compare results after changing one input
- → save an estimate for planning or comparison