Amps to Watts Calculator
Easily convert electrical current (amps) to real power (watts) for single-phase and three-phase circuits
Calculation Result
Real Power (Watts)
Real Power (Kilowatts)
Formula Used:
Calculation Formulas
Single Phase
Watts = I × V × PF
Three Phase
Watts = I × V × PF × √3
Where: I = Current (Amps), V = Voltage (Volts), PF = Power Factor, √3 ≈ 1.732
Kilowatts (kW) = Watts (W) / 1000
Common Examples
Example 1: 10A, 220V, 0.85 PF (Single Phase)
Watts = 10 × 220 × 0.85 = 1,870 W (1.87 kW)
Example 2: 15A, 380V, 0.9 PF (Three Phase)
Watts = 15 × 380 × 0.9 × 1.732 = 8,850 W (8.85 kW)
Example 3: 5.5A, 120V, 0.95 PF (Single Phase)
Watts = 5.5 × 120 × 0.95 = 627 W (0.63 kW)
Frequently Asked Questions (FAQ)
Power Factor (PF) is the ratio of real power (Watts) to apparent power (VA) in AC circuits, ranging from 0.01 to 1. It’s critical because it indicates how efficiently electrical power is used—higher PF (closer to 1) means better efficiency, lower energy waste, and reduced utility costs.
Single-phase is used for residential and small commercial applications (110V/220V, 120V/240V). Three-phase is for industrial equipment, large motors, and high-power systems (380V/480V), as it delivers more power efficiently with balanced loads.
Watts (real power) is the actual power consumed by the load to perform work. VA (apparent power) is the total power drawn from the source (product of voltage and current). The relationship is: Watts = VA × Power Factor. Resistive loads (heaters, lights) have PF ≈ 1, so Watts ≈ VA; inductive/capacitive loads (motors, transformers) have lower PF, so Watts