Volts to kW Calculator

Nameplate ratings on industrial and commercial equipment rarely match measured operation. A 110kW motor labelled at 415V three-phase typically draws 75 to 90kW under partial load, and that gap is where supply capacity is either wasted or under-provisioned. Converting measured voltage and current into a real-power figure in kW is the working tool engineers use to compare what the supplier datasheet says to what the meter actually sees. The answer drives every downstream decision about transformer sizing, MIC headroom and tariff selection.

For mid-market businesses with 5 to 50 sites, this calculation feeds directly into bill auditing. If the half-hourly data on a site shows 65kW of steady demand against a 100kW MIC, the operator is paying availability charges on capacity that is not being used. Reducing the MIC saves on the standing capacity element of the non-commodity cost (NCC) stack. Conversely, if measured power is creeping above MIC, the site is exposed to excess capacity charges, which on a DUoS bill can be 4 to 8 times the standard rate per kVA.

Purely Energy works with finance and facilities teams to turn voltage and current measurements (from on-site sub-metering or our Purely Insights platform) into the right kW figure for the supply contract decision. We size capacity correctly across portfolios, renegotiate MIC where it makes sense, and feed the data back into the procurement strategy so the contract reflects the operation rather than a guess made five years ago. That is what we mean when we say we work for the buyer, not the supplier.