Sizing tools
Capacity and runtime are two separate purchases, and they get sized two different ways. One calculator for each — both show their working, so you can check the answer against your consultant’s.
UPS kVA calculator
List what goes on the UPS, set the power factor and headroom, and get the model to specify — with the working shown.
Our units are rated at 0.8 power factor, so the calculator defaults to it and maps the answer onto the eleven ratings we actually build.
Open the calculatorBattery backup time calculator
Work out how long a bank will genuinely hold your load, rather than what amp-hours times volts suggests.
Derates for the discharge rate, which is the step most online calculators skip — a lead-acid bank rated at C20 delivers roughly half its printed capacity in a one-hour discharge.
Open the calculatorBoth are estimates
Neither tool accounts for motor inrush, harmonic loading or phase imbalance, and any of those can move the answer substantially. For anything with motors on it, or above about 20 kVA, send us the load list instead and we will size it properly.
Send a load list