How to use it
- Enter rated or measured UPS capacity in Wh.
- Enter the connected load in watts.
- Set expected efficiency and calculate.
UPS Runtime Calculator
Estimate backup runtime from UPS energy capacity and load.
This is an estimate. Actual UPS runtime depends on battery age, load profile, UPS model, and manufacturer ratings.
About the UPS Runtime Calculator
Estimate idealized runtime using a UPS energy capacity, connected equipment load and an efficiency allowance.
Formula
Runtime hours = capacity Wh × efficiency ÷ 100 ÷ load watts. Minutes equal hours × 60.
Example
A 1,000 Wh UPS at 85% efficiency supporting a 500 W load produces an ideal estimate of 1.7 hours.
Notes
UPS discharge curves are nonlinear and quoted VA ratings are not the same as usable Wh. Follow the manufacturer runtime chart for equipment planning.