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SolarEvaluator

UPS Sizing Calculator

Free UPS tool

UPS Sizing Calculator

Enter your connected devices and desired backup time. Get the exact UPS VA rating, watt capacity, and battery runtime recommendation.

Quick add devices

Connected devices

DeviceWatts
Total load0 W
Required VA0 VA
Recommended UPS0 VA
Battery energy needed0 Wh

UPS sizing accounts for power factor and a 25% safety margin. Actual battery runtime varies by UPS model, battery age, temperature, and load profile. Always verify runtime specs in the UPS datasheet.