UPS Battery Sizing Calculator
Size an uninterruptible power supply for your home office. Calculate VA rating, battery capacity, and runtime for your equipment.
Inputs
W
W
W
W
min
Results
Minimum VA Rating
650 VA
Total Load390 W
Recommended UPS Size900 VA
Battery Capacity Needed109 Wh
Estimated Actual Runtime11.2 min
Estimated Cost$90
How to Use This Calculator
- Enter the wattage of each device: Computer Watts, Monitor Watts, Router Watts, and Other Watts for your workstation.
- Set Desired Runtime (minutes) — typically 10–30 minutes for graceful shutdown or longer for extended outages.
- Review Total Load (W) to ensure it does not exceed the UPS's rated wattage capacity.
- Check Required VA and Recommended VA — UPS units are rated in VA; always size up to the next standard model.
- Review Battery Wh and Estimated Runtime to verify the UPS will actually run your equipment for the target duration.
- Use Estimated Cost to compare UPS brands at the recommended VA rating and select the right capacity.
Ad Placeholder
Related Calculators
Backup Generator Runtime Calculator
Estimate generator runtime based on fuel tank size, connected load, and fuel type. Calculate fuel consumption and operating costs.
Whole-House Surge Protector Calculator
Size a whole-house surge protector for your electrical panel. Calculate kA rating, cost, and ROI based on your home and risk profile.
EV Charger Circuit Calculator
Size the electrical circuit for a Level 2 EV charger: breaker, wire gauge, daily energy needs, and charging costs.
Ad Placeholder