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.
* Use e for scientific notation. E.g: 5e3, 4e-8, 1.45e12
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):
Example
P = 200W, V = 40V
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):
The power factor of resistive impedance load is equal to 1.
Example
P = 2000W, V = 110V, PF = 0.8
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):
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):
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 |
|---|---|
| Resistive load | 1 |
| Fluorescent lamp | 0.95 |
| Incandescent lamp | 1 |
| Induction motor full load | 0.85 |
| Induction motor no load | 0.35 |
| 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.
