Watts to Amps Calculator

Convert electric power in Watts (W) to electric current in Amps (A).

W
V

How to Convert Watts to Amps

Watt (W) is the unit of electric power, measuring the rate of energy transfer.

Ampere (A) is the unit of electric current, measuring the flow of electric charge.

Calculating Amps from Watts requires knowing the voltage and the type of current (DC or AC).

DC Amps Calculation Formula

For DC circuits, current (in Amps) is equal to the power (in Watts) divided by the voltage (in Volts).

I(A) = P(W) / V(V)

AC Amps Calculation Formula

For AC circuits, the Power Factor (PF) must be included.

Single Phase AC

I(A) = P(W) / (V(V) × PF)

Three Phase AC (Line-to-Line Voltage)

I(A) = P(W) / (√3 × VL-L(V) × PF)

Three Phase AC (Line-to-Neutral Voltage)

I(A) = P(W) / (3 × VL-N(V) × PF)

Typical Power Factor Values

Do not use typical power factor values for accurate calculations.

Appliance / Load Power Factor
Resistive load (Heater, Incandescent light)1.0
LED / Fluorescent lamp0.95
Induction Motor (Full load)0.85
Induction Motor (No load)0.35

Calculation Example

Question: A device consumes 1200 Watts at 120 Volts. What is the current?

Answer:
I = 1200 W / 120 V = 10 Amps

Watts to Amps Conversion Table

The table below shows current values for various power levels at 120V.

Power (Watts) Voltage (Volts) Current (Amps)
100 W120 V0.83 A
500 W120 V4.17 A
1000 W120 V8.33 A
1200 W120 V10.00 A
1500 W120 V12.50 A
2000 W120 V16.67 A
2400 W120 V20.00 A
3000 W120 V25.00 A
4000 W120 V33.33 A
5000 W120 V41.67 A