Electrical Power Calculator: Watts, kW, kVA, HP and Amps
Choose DC, single-phase or three-phase, then enter volts and amps to get power, or watts to get the current. Power factor is included for AC.
- Nothing you type is stored
- Free
- No signup
Power
2.07kW
- Power
- 2,070 W
- Apparent power
- 2.3 kVA
- Horsepower
- 2.77 HP
Real power = volts × amps × power factor.
Show working
- P = 230 × 10 × 0.9 = 2,070 W
How to use
- Choose whether to find power or current.
- Pick DC, single-phase or three-phase and enter the voltage.
- Enter amps (or watts) and the power factor for AC loads.
Good to know
DC: P = V × I. Single-phase AC: P = V × I × PF. Three-phase AC: P = √3 × V(line) × I × PF. Apparent power S (VA) is the same without PF. 1 HP = 746 W.
Indian supply: 230 V single-phase and 415 V (line to line) three-phase at 50 Hz (400 V is the newer nominal value). Power factor is 1 for heaters and geysers, about 0.8–0.9 for motors, fans and ACs.
Use the current result to pick an MCB and cable, together with the Wire size calculator. Starting current of motors and compressors can be several times the running current.
Questions
How many amps is 2 kW at 230 V?
For a heater (PF 1): 2000 ÷ 230 = 8.7 A. For a motor at PF 0.85: about 10.2 A.
What is the difference between kW and kVA?
kW is real power that does work; kVA is volts × amps. kW = kVA × power factor.
How many watts is 1 HP?
746 W (0.746 kW).
Which voltage should I use for three-phase?
The line-to-line voltage, usually 415 V (or 400 V) in India.
What power factor should I enter?
1 for resistive loads; 0.8–0.9 for motors, pumps and ACs; check the rating plate.