Power conversion
How to estimate kW from amps
Turn a measured or design current into a transparent preliminary active-power estimate.
Open amps to kW calculator →
What this calculation is for
Current alone does not state active power. This guide shows how voltage and, on AC systems, power factor combine with current to give a preliminary kW estimate.
How to use the calculator
- Select DC, single-phase AC, or balanced three-phase AC.
- Enter the measured or design current and nominal operating voltage.
- For AC systems, enter the measured or assumed power factor.
- Compare the output with known load data and review the calculation trace.
Useful for
- • Rough load survey
- • Checking a load-schedule entry
- • Comparing a measured circuit with its expected demand
Fields explained
Current
The measured or design line current in amperes.
Voltage
Nominal or measured voltage for the same operating point.
Power factor
Required for AC active-power estimates.
System type
Determines whether the calculation uses one phase or a balanced three-phase relationship.
Important limits and next checks
Preliminary engineering aid only. This article and its calculator do not provide an approval, certificate, compliance determination or installation instruction.
- A clamp-meter reading can vary with load state; capture the operating condition.
- Do not use this output as a substitute for an energy study or a verified equipment rating.
Verify applicable laws, rules, standards, manufacturer data and project conditions with a qualified electrical professional before construction, procurement or regulatory submission.