Amperage calculator: kW to amps for DC, single and three phase
Current depends on power, voltage and supply type. For 10 kW of active electrical input at PF = 1, 230 V single phase gives about 43.48 A; balanced three phase at 400 V gives about 14.43 A per line. Enter your own power and voltage below; do not add three line currents together.
Calculate with your assumptions
Choose the correct supply and voltage
For DC, I = P / V. For single-phase AC active input, I = P / (V × PF). For balanced three phase, I = P / (√3 × U × PF), using line-to-line voltage U. Enter power in kW; the calculation multiplies it by 1000 to obtain watts. Power factor is ignored for DC.
Input power or shaft output?
When the equipment rating is mechanical shaft output, divide that power by efficiency η before calculating the electrical current. If the rating already states active electrical input, do not apply efficiency again. Apparent power in kVA is different from active power in kW; use the appropriate equipment rating. PF equals cos φ only for sinusoidal voltage and current.
Check the worked result
At 400 V balanced three phase, 10 kW shaft output with PF = 0.8 and η = 0.9 gives approximately 20.05 A per line. A 5 kW DC input at 230 V gives approximately 21.74 A. These examples state their assumptions and are not equipment or supply recommendations.
What current alone cannot determine
Cable cross-section, protective device rating, installation method, ambient temperature, grouping, voltage drop, fault protection and starting current need separate assessment. This steady-state calculator does not model harmonics, unbalanced phases, transient peaks or select a fuse, breaker or cable.
Examples with stated assumptions
| Inputs and method | Result |
|---|---|
| 10 kW input, 230 V, 1 phase, PF 1 | 43.48 A |
| 10 kW input, 400 V, 3 phase, PF 1 | 14.43 A per line |
| 10 kW shaft, 400 V, PF 0.8, η 0.9 | 20.05 A per line |
Result scope
Schneider Electric's formula source was checked on 7 October 2026. Use the stated supply and power definition; current calculation is separate from installation design.