VA to kW Calculator

VA to kW is the conversion that separates what your infrastructure has to support from what your supplier actually bills you for. The kVA figure drives transformers, generators, UPS units, cables and breaker ratings. The kW figure drives the energy charge on your invoice, your SECR scope 2 reporting and your carbon accounting. The connecting variable is power factor: a load drawing 100 kVA at 0.92 power factor only consumes 92 kW of real power, but the supply still has to be designed for the full 100 kVA. Ignoring the gap is how sites end up overbuilt and overcharged at the same time.

For finance leads modelling the case for a new production line, an additional refrigeration plant, an EV fleet or a data hall expansion, the VA to kW conversion sets the bottom of the cost stack. The kW number drives the monthly commodity bill, the carbon footprint and the SECR submission. The kVA number drives the connection cost, the DNO conversation and the standing charges. Treating the two figures as interchangeable (and many capex business cases do) consistently understates either capacity risk or energy cost. A clean conversion at the assumption stage lets the rest of the model breathe.

Across the Purely Energy book we see power factor sitting between 0.85 and 0.98 on a typical I&C site, and the swing from one end to the other rewrites the reactive charge on the DUoS line of the bill significantly. The first question on a contract review is almost always whether the power factor is high enough to avoid reactive penalties, and the second is whether the contracted kW and kVA capacity figures still match reality. Both questions start with this VA to kW conversion, applied to the half-hourly meter data rather than the nameplate.