kVA to kW Calculator
Convert apparent power in kilovolt-amps (kVA) to real power in kilowatts (kW). Enter the apparent power and the power factor (between 0 and 1), and press Calculate to get real power using P(kW) = S(kVA) × PF. Everything runs locally in your browser.
Enter the apparent power
Type the apparent power S in kilovolt-amps (kVA) — the rating you read off a generator, UPS, or transformer nameplate. Negative values are rejected; 0 kVA is valid.
Enter the power factor
Type the power factor PF, a decimal between 0 and 1 — typically 0.7 to 0.95 for motor loads, or the value printed on the equipment nameplate. PF = 1 means purely resistive load.
Press Calculate, read kW
The real power P appears in kilowatts (kW): P = S × PF. For example, 10 kVA at PF 0.8 gives 8 kW. Copy the result to your clipboard, or press Reset to start over.
kVA to kW calculation
- kVA to kW formula
- The real power P in kilowatts (kW) is equal to the apparent power S in kilovolt-amps (kVA), times the power factor PF: P(kW) = S(kVA) × PF. For example, 10 kVA at a power factor of 0.8 gives 10 × 0.8 = 8 kW.
- What is the power factor?
- The power factor is the ratio of real power (kW) to apparent power (kVA) in an AC circuit: PF = P / S. It is a dimensionless number between 0 and 1 — 1 for a purely resistive load (heaters, incandescent lamps), and lower for inductive loads such as motors and transformers that circulate reactive power.
- Worked examples
- A 100 kVA generator at PF 0.85 delivers 100 × 0.85 = 85 kW. A 12.5 kVA UPS at PF 0.9 supplies 12.5 × 0.9 = 11.25 kW. At PF 1, real power equals apparent power: 5 kVA × 1 = 5 kW. At PF 0, no real power is delivered at all: 10 kVA × 0 = 0 kW.
- Why is kVA not the same as kW?
- kVA measures apparent power — the total voltage-ampere product the source must supply. kW measures real power — the portion actually doing work. With reactive (inductive or capacitive) loads the two differ by the power factor, which is why generator and transformer nameplates are rated in kVA while loads are rated in kW.
- What inputs does the calculator reject?
- Empty or non-numeric fields, negative apparent power (kVA cannot be negative), and any power factor outside 0 to 1 — a PF above 1 or below 0 is not physically realizable. The result is only produced when both inputs are valid; a validation message tells you which field to fix.
Privacy: every calculation runs in your browser tab — no value you type is sent anywhere. Copy result uses your clipboard only. Results assume sinusoidal steady-state values; verify real installations with a meter.