ConverterAmps to Watts Calculator
Calculate active power from a known current only after selecting the electrical system and entering its voltage. AC modes also require a power-factor magnitude; the three-phase option uses a balanced-system equation with line-to-line RMS voltage and line current.
Signed current is accepted as a mathematical direction convention. Voltage must be positive. AC power factor must be greater than 0 and no more than 1. Results display up to six decimal places.
Choose The Electrical Model First
For DC, the calculator uses P = V x I. Single-phase AC uses P = Vrms x Irms x PF. Balanced three-phase AC uses P = sqrt(3) x VLL,rms x Iline,rms x PF. It never inserts an unseen 120 V assumption.
What The Result Does Not Decide
The output is an active-power calculation, not a wire-size, breaker-size, conductor-ampacity, startup-current, short-circuit, protection, or code-compliance result. Use the equipment documentation and applicable electrical requirements for those decisions.
Useful Checks Before Copying
- Confirm whether the source is DC, single-phase AC, or balanced three-phase AC.
- For three-phase input, use line-to-line RMS voltage and line RMS current.
- Keep the mode, voltage, and power factor with the copied watt result.
Frequently Asked Questions
No. Current needs voltage, and AC active power may also need power factor and phase context.
No. This calculator expects the magnitude of active power divided by apparent power for the selected AC calculation; efficiency describes a different input-output relationship.
It assumes a balanced three-phase system and uses line-to-line RMS voltage with line RMS current. It does not model an unbalanced system.
The calculator allows a signed current so the sign can represent direction under a declared mathematical convention. It does not mean every real installation uses the same sign convention.