Amps to Watts Calculator — Instant A ↔ W Converter

Convert amps to watts and watts to amps instantly. Pick your voltage — 12 V, 24 V, or 48 V DC battery systems, or 120 V / 240 V AC household circuits — type a value in either box, and the other updates live. Includes a power-factor option for AC circuits and a full 1–100 amp reference table.

10 A × 120 V × PF 1.0 = 1,200 W

1–100 A in watts at 120 V AC (PF 1.0)

The conversion formula

DC and AC resistive loads: Watts = Amps × Volts. AC loads with motors or electronics: Watts = Amps × Volts × Power Factor. Power factor accounts for the phase shift between voltage and current — a 10 A motor at 120 V with PF 0.85 delivers 1,020 W of real power, not 1,200 W. Battery systems (12/24/48 V DC) always use PF 1.

For three-phase AC, multiply by √3 (1.732) as well. When sizing wire or breakers from a wattage, remember the NEC 125% continuous-load rule — our breaker sizing calculator handles that automatically.