# Watts to Amps Calculator

Convert power in watts (W) to electrical current in amperes (A). Ideal for understanding the current requirements of electrical systems and devices. Obtain an estimation of amperes from watts using this practical online tool.

A
mA

* Use e for scientific notation. E.g: 5e3, 4e-8, 1.45e12

Related

## What is Watts to Amps Calculator

To convert watts (W) to amps (A), you need to know the voltage (V) of the circuit. The formula for converting watts to amps is:

Amps (A) = Watts (W) / Volts (V)

To calculate the current in amps, divide the power in watts by the voltage.

For example, if you have a circuit with a power consumption of 1000 watts (W) and a voltage of 120 volts (V), you can calculate the current in amps as follows:

Amps (A) = 1000 W / 120 V Amps (A) ≈ 8.33 A

In this example, the current flowing through the circuit would be approximately 8.33 amps.

It's important to note that this calculation assumes a direct conversion from watts to amps when considering resistive loads where the power factor is 1. However, for circuits with reactive components or loads with different power factors, additional considerations may be required to accurately determine the current in amps.

## DC watts to amps calculation

The current I in amps (A) is equal to the power P in watts (W), divided by the voltage V in volts (V):

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

### Example

P = 200W, V = 40V

I =
200W40V
= 5A

## AC single phase watts to amps calculation

The phase current I in amps (A) is equal to the power P in watts (W), divided by the power factor PF times the RMS voltage V in volts (V):

I(A) =
P(W)PF × V(V)

The power factor of resistive impedance load is equal to 1.

### Example

P = 2000W, V = 110V, PF = 0.8

I =
2000W0.8×110V
= 22.72727A

## AC three phase watts to amps calculation

### Calculation with line to line voltage

The phase current I in amps (A) is equal to the power P in watts (W), divided by square root of 3 times the power factor PF times the line to line RMS voltage VL-L in volts (V):

I(A) =
P(W)3 × PF × VL-L(V)

The power factor of resistive impedance load is equal to 1.

### Calculation with line to neutral voltage

The phase current I in amps (A) is equal to the power P in watts (W), divided by 3 times the power factor PF times the line to neutral RMS voltage VL-N in volts (V):

I(A) =
P(W)3 × PF × VL-N(V)

The power factor of resistive impedance load is equal to 1.

## Typical power factor values

Do not use typical power factor values for accurate calculations.

Device Typical power factor
Fluorescent lamp 0.95
Incandescent lamp 1
Resistive oven 1
Synchronous motor 0.9

## Watts to amps table (120V)

Power (W) Voltage (V) Current (A)
10 watts 120 volts 0.0833 amps
20 watts 120 volts 0.167 amps
30 watts 120 volts 0.250 amps
40 watts 120 volts 0.333 amps
50 watts 120 volts 0.417 amps
60 watts 120 volts 0.500 amps
70 watts 120 volts 0.583 amps
80 watts 120 volts 0.667 amps
90 watts 120 volts 0.750 amps
100 watts 120 volts 0.833 amps
200 watts 120 volts 1.667 amps
300 watts 120 volts 2.500 amps
400 watts 120 volts 3.333 amps
500 watts 120 volts 4.167 amps
600 watts 120 volts 5.000 amps
700 watts 120 volts 5.833 amps
800 watts 120 volts 6.666 amps
900 watts 120 volts 7.500 amps
1000 watts 120 volts 8.333 amps

## Watts to Amps Calculator Example

Amps (A) = Watts (W) / Volts (V)

Here's an example table that demonstrates the calculation of amps from watts for different voltage values:

Watts (W) Volts (V) Amps (A)
100W 120V 0.833A
200W 240V 0.833A
150W 110V 1.364A
75W 220V 0.341A

To calculate the amps, divide the given watts by the corresponding voltage. For example, if you have 100W and 120V:

Amps (A) = 100W / 120V Amps (A) ≈ 0.833A

Therefore, for 100W and 120V, the current is approximately 0.833A.

Similarly, perform the calculation for other examples in the table using the given wattage and voltage values.

It's important to note that this calculation is valid as long as you have a constant voltage in the circuit. If the voltage varies, you may need to consider additional factors or use more advanced calculations.