Power conversion
How to convert kW to amps for preliminary electrical work
Understand the relationship between power, voltage, power factor and efficiency before estimating current.
Open kW to amps calculator →
What this calculation is for
This guide explains a preliminary conversion from active power to current for DC, single-phase AC and balanced three-phase AC loads. It is useful for an early design check, not for equipment selection or a compliance assessment.
How to use the calculator
- Choose the system type: DC, single-phase AC, or balanced three-phase AC.
- Enter a realistic operating voltage and the electrical power input.
- For AC, enter power factor. If the value is mechanical output power, identify efficiency before converting.
- Review the substituted formula, assumptions and result before taking the next design step.
Useful for
- • First-pass circuit current estimate
- • Load-schedule row check
- • Comparing likely current across supply systems
Fields explained
Power
The requested load in W or kW. Electrical input and mechanical output are not interchangeable.
Voltage
The system voltage at the point relevant to the calculation.
Power factor
For AC loads, the fraction linking apparent and active power.
Efficiency
Used only when converting mechanical output to electrical input.
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.
- Starting current, harmonics, duty cycle and diversity are outside this simple conversion.
- Confirm equipment nameplate data and applicable local requirements before selecting conductors or protection.
Verify applicable laws, rules, standards, manufacturer data and project conditions with a qualified electrical professional before construction, procurement or regulatory submission.