Check one measured load against exact UPS watt and VA ratings, interpolate only inside a first-party runtime-curve bracket, and expose shutdown surplus.
Can this UPS carry the load long enough for shutdown?
The load must pass both watt and VA limits, sit inside two verified manufacturer curve points, and leave runtime beyond the required shutdown window. VA alone never proves runtime.
Method
Required VA equals measured watts divided by load power factor. Runtime uses bounded log-log interpolation between two exact manufacturer points; the tool refuses extrapolation.
Important limitation
Battery age, temperature, startup peaks, firmware and load behavior can change runtime. Never use this planning result for life-safety loads; run a controlled shutdown test.
What the result cannot know
Battery age, temperature, startup peaks, firmware and load behavior can change runtime. Never use this planning result for life-safety loads; run a controlled shutdown test.
