Watts / Volts / Amps / Ohms Calculator

Ohm's law and the power equations sit behind every electrical decision on a commercial site, from cable sizing to transformer specification to fault-level calculations. Solving any of V = IR, P = VI, P = I squared R or P = V squared over R from two known values is the daily work of the engineer carrying out a supply audit. Doing it in one place, with consistent units, removes the small arithmetic errors that propagate through a design and end up overstated on the bill of materials or understated on the loss calculation.

On a multi-site portfolio, the same calculations get repeated thousands of times across different supply voltages (230V single-phase, 400V three-phase, 11kV HV, 33kV at very large sites). The risk is not in the maths, it is in the consistency of the assumptions: which voltage to use, how to handle power factor on AC, how to size for diversity. A single working tool that handles all four permutations gives engineers a reliable starting point and keeps the audit traceable when it gets reviewed at board level.

Purely Energy supports clients with portfolio-wide audits as part of contract renewal and as standalone capacity reviews. We combine the electrical engineering work (cable sizing, supply capacity, transformer loading) with the commercial procurement work (MIC, MEC, NCC, tariff selection) into a single recommendation that finance can approve. For Industrial & Commercial clients consuming 10 GWh per year and above, that integrated approach typically pays for itself inside the first contract year.