100% Free Tool

Watts to Amps Calculator

Convert between watts, volts, amps, and ohms. Supports DC, AC single-phase, and AC three-phase calculations.

SOLVE

Power (Watts)

Unit: W (Watts)

SOLVE

Voltage (Volts)

Unit: V (Volts)

SOLVE

Current (Amps)

Unit: A (Amperes)

SOLVE

Resistance (Ohms)

Unit: Ohms

Power Factor: (0 to 1, default 0.85)

CURRENT (AMPS)

Amperes (A)

Formula Used

I = P / V

Key Formulas

DC Power

P = V x I

Power = Voltage x Current

DC Current

I = P / V

Current = Power / Voltage

AC Single Phase

P = V x I x PF

Power = Voltage x Current x Power Factor

AC Three Phase

P = sqrt(3) x V x I x PF

Power = 1.732 x Voltage x Current x PF

Ohm's Law

V = I x R

Voltage = Current x Resistance

Power from Resistance

P = I^2 x R

Power = Current squared x Resistance

Quick Reference Table

Device / Appliance	Power (W)	Voltage (V)	Current (A)	Type
Phone Charger	5 - 20	5 - 20	0.5 - 1	DC
LED Light Bulb	6 - 15	120 / 230	0.05 - 0.13	AC
Laptop	45 - 100	19 - 20	2.5 - 5	DC
Fan (Ceiling)	50 - 80	120 / 230	0.3 - 0.7	AC
Refrigerator	100 - 250	120 / 230	0.8 - 2.2	AC
Microwave Oven	600 - 1200	120 / 230	5 - 10	AC
Washing Machine	500 - 2000	120 / 230	4 - 17	AC
Air Conditioner (1 Ton)	1000 - 1500	230	4.3 - 6.5	AC
Electric Heater	1500 - 3000	120 / 230	12.5 - 26	AC
Electric Stove	2000 - 5000	230	8.7 - 21.7	AC 3-ph
Water Heater	3000 - 5500	230	13 - 24	AC
EV Charger (Level 2)	7200 - 19200	240	30 - 80	AC

How It Works

Select Type

Choose DC, AC Single Phase, or AC Three Phase based on your circuit.

Enter Values

Input any two known values (watts, volts, amps, or ohms).

Set Solve Target

Click the input field you want to solve for - it gets marked as SOLVE.

Get Result

Click Calculate to instantly see the missing value with the formula used.