Convert Watts to Amps

How to convert Watts into Amps?

To convert Watts (W) into Amps (A), you need to know the voltage (V) in the circuit.

DC Circuits

The formula to convert Watts into Amps is:

Amps (A) = Watts (W) ÷ Volts (V)

Or

A = W / V

Examples:

1. Watts (W) = 600W, Volts (V) = 120V
   Amps (A) = W / V
   A = 600W / 120V = 5A
2. W = 480W, V = 240V
   A = 480W / 240V = 2A
3. W = 120W, V = 12V
   A = 120W / 12V = 10A

AC Circuits (With Power Factor)

In AC circuits (especially those with inductive or capacitive loads such as motors, transformers, or fluorescent lighting), the power factor (PF) must be taken into account.

Power Factor (PF) is a number between 0 and 1 that represents how efficiently the circuit converts current into useful work. A PF of 1.0 is ideal (purely resistive load). Most real-world AC loads have a PF between 0.7 and 0.95.

Single-Phase AC Formula:

Amps (A) = Watts (W) ÷ (Volts (V) × Power Factor (PF))

or

A = W / (V × PF)

Examples:

1. Watts = 600W, Volts = 120V, Power Factor = 0.8
   A = 600 / (120 × 0.8) = 600 / 96 = 6.25A
2. W = 1500W, V = 240V, PF = 0.85
   A = 1500 / (240 × 0.85) = 1500 / 204 ≈ 7.35A
3. W = 1000W, V = 230V, PF = 0.9
   A = 1000 / (230 × 0.9) = 1000 / 207 ≈ 4.83A

Three-Phase AC Formula (common in industrial applications):

Amps (A) = Watts (W) ÷ (√3 × Volts (V) × Power Factor (PF))
or
A = W / (1.732 × V × PF)

Example:

W = 5000W, V = 400V (line-to-line), PF = 0.85

A = 5000 / (1.732 × 400 × 0.85) ≈ 5000 / 588.88 ≈ 8.49A