Amps to Watts Calculator
Amps to Watts Calculator
Converting amps to watts tells you how much power a circuit or device consumes. This is useful for sizing generators, checking if a circuit is overloaded, and comparing energy costs.
Conversion Formula
DC: W = A × V. AC single phase: W = A × V × PF. Three phase: W = A × V × PF × 1.732. Power factor represents the ratio of real power to apparent power.
Step-by-Step Examples
10A, 120V, DC = 1200 W
10 × 120 = 1200 watts
10A, 120V, AC 1ph, PF=0.9 = 1080 W
10 × 120 × 0.9 = 1080 watts
Frequently Asked Questions
How do I convert amps to watts?
For DC: multiply amps by volts (W = A × V). For AC single phase: W = A × V × PF. For three phase: W = A × V × PF × √3.
Can I convert amps to watts without knowing the voltage?
No. Power (watts) depends on both current (amps) and voltage (volts). You must know the voltage to calculate watts.
What power factor should I use for common appliances?
Resistive loads like heaters and incandescent bulbs have PF = 1.0. LED drivers: 0.9-0.95. Motors: 0.7-0.9. Switching power supplies: 0.6-0.99. When in doubt, use 0.8 as a conservative estimate.