Free calculator · Backup power
Generator Steady-State Load Calculator
Calculate a steady-state kW/kVA envelope before consulting a generator manufacturer’s transient sizing tool.
Interactive calculator · explicit assumptions
Generator Steady-State Load Calculator
Calculations run in your browser. Sharing puts numeric assumptions in the link. No registration required.
Formula
Planning kW = running kW × (1 + reserve % ÷ 100). Planning kVA = planning kW ÷ PF.
Worked example
500 kW with 20% reserve and PF 0.8 gives a planning envelope of 600 kW and 750 kVA.
What this calculation does not cover
Does not select a generator or model motor starting, UPS rectifiers, harmonics, load-step acceptance, altitude, fuel, emissions, standby/prime ratings or redundancy.
Using the result responsibly
Keep a record of the input units and operating assumptions. A change in one input can make two apparently similar equipment options impossible to compare. Export the scenario before reviewing it with your engineer or equipment manufacturer.
Educational planning only. These tools do not replace a licensed professional’s design, a manufacturer selection study or applicable local requirements.