Home Calculators Watts to Amps Calculator

Watts to Amps Calculator

Convert watts to amperes for DC, AC single-phase, and AC three-phase circuits. Enter power and voltage to instantly get current — with full formula breakdown and common appliance reference.

Supports DC · AC Single-Phase · AC Three-Phase · Power Factor included

Circuit Type

Select the type of electrical circuit for the correct formula

I = P ÷ V
W

Enter power in Watts (W) or kilowatts below

V

Common: 12V (auto), 120V (US), 230V (EU), 240V (AU)

Live Result
8.33
Amperes (A)
Power1000 W
Voltage120 V
CircuitDC
Current8.33 A
Ohm's Law & Power
I = P ÷ V
P = V × I
V = P ÷ I
R = V ÷ I
I= Current (Amperes, A)
P= Power (Watts, W)
V= Voltage (Volts, V)
R= Resistance (Ohms, Ω)
PF= Power Factor (0–1)
AC Formulas
DC
I = P ÷ V
AC Single-Phase
I = P ÷ (V × PF)
AC Three-Phase
I = P ÷ (√3 × V × PF)

√3 ≈ 1.7321 · For three-phase, V is the line-to-line voltage.

Breaker Sizing Rule
NEC 80% Rule — Circuit breakers should not be loaded above 80% of their rated amperage for continuous loads (>3 hrs). Divide your calculated amps by 0.8 to find minimum breaker size.
Standard breaker sizes — 15A, 20A, 30A, 40A, 50A, 60A, 100A, 150A, 200A. Always round up to the next standard size.
Wire gauge — 15A circuit → 14 AWG · 20A → 12 AWG · 30A → 10 AWG · 40–50A → 8 AWG. Always consult NEC or a licensed electrician.