kVA to kW Calculator

kVA is apparent power, the total the network must supply. kW is real power, the part that does useful work. The two are linked by power factor: kW = kVA x power factor. The gap between them is reactive power, drawn by motors, transformers and other inductive equipment to maintain magnetic fields. At a power factor of 1.0 the two are equal; at 0.8, a 100 kVA supply yields only 80 kW.

Multiply by power factor: kW = kVA x PF. A 500 kVA transformer feeding a site at 0.8 power factor can deliver 400 kW of real power; raise the power factor to 0.95 and the same transformer supports 475 kW. This is why power factor correction is often cheaper than upgrading a supply when a site is running out of capacity.

Measure rather than guess where you can: half-hourly meter data or your supplier portal usually shows kW and kVA side by side, and dividing one by the other gives your actual power factor. As a rough engineering guide, motor-heavy industrial sites often sit around 0.8, mixed commercial loads around 0.9 to 0.95, and modern IT or LED-dominated loads close to unity. The calculator lets you test the sensitivity in seconds.

Because the distribution network is constrained by current, and current follows apparent power, not real power. The DNO must size its cables and transformers for the full kVA your site draws, including the reactive component, so capacity is agreed and charged in kVA. A site with a poor power factor uses up more of its agreed capacity for the same useful kW, which is why correcting power factor can defer a costly connection upgrade.

No. Power factor is at most 1.0, so real power can never exceed apparent power; kW equals kVA only for a purely resistive load such as an electric resistance heater. If a conversion appears to show kW above kVA, either the power factor has been entered as a percentage (use 0.95, not 95) or the two readings were taken at different times.