Amps to Watts to Volts Converter for Any Two Values
Solve for amps, watts, or volts from the other two using P = V × I, with power factor and three-phase options — a planning figure, not a wiring authorization.
= 1,200 W
How it works
Amps, watts, and volts are tied together by the power law. In a direct-current or single-phase resistive circuit, power equals voltage times current: W = V × A. Rearrange it and you can solve for whichever value you are missing — A = W ÷ V or V = W ÷ A. This calculator lets you pick what to solve for, enter the two values you know, and reads out the third. It is a quick planning and learning tool; a licensed electrician should confirm any figures used for real wiring.
Alternating-current circuits add power factor. Real power in watts equals volts times amps times the power factor, a number between 0 and 1 that reflects how well voltage and current stay in step. For purely resistive loads like heaters and incandescent lamps the power factor is 1, so W = V × A holds exactly. Motors and electronics run lower, often 0.8 to 0.95, which means they draw more current than their wattage alone suggests.
Three-phase power brings in a √3 factor. For a balanced three-phase load, real power equals √3 × V × A × power factor, using the line-to-line voltage. That is why the same current at 480 V three-phase moves far more power than at 120 V single-phase. Toggle the phase and enter a power factor, and the calculator applies the right formula automatically.
W = √3 × 480 V × 100 A × 0.9
W = 1.732 × 480 × 100 × 0.9 = 74,825 W (about 74.8 kW)