Watts to Amps Calculator – Convert Watts to Amps

Our watts to amps calculator is an invaluable tool that helps convert electrical power (measured in watts) to electrical current (measured in amperes or amps).

Imagine you have a 60-watt light bulb and want to know how much current it draws when connected to a 120-volt outlet. This watts to amps converter would quickly tell you that the bulb draws 0.5 amps.

• 150 watts at 120 volts: Amps = 150 watts / 120 volts = 1.25 amps
• 20 watts at 120 volts: Amps = 20 watts / 120 volts ≈ 0.167 amps

At 120 volts, 150 watts is approximately 1.25 amps, and 20 watts is approximately 0.167 amps.

Watts to Amps Calculator

At 120 Volts

Watts (W)	Amps (A)
100 W	0.83 A
200 W	1.67 A
300 W	2.50 A
400 W	3.33 A
500 W	4.17 A
600 W	5.00 A
700 W	5.83 A
800 W	6.67 A
900 W	7.50 A
1000 W	8.33 A
1100 W	9.17 A
1200 W	10.00 A
1300 W	10.83 A
1400 W	11.67 A
1500 W	12.50 A
1600 W	13.33 A
1700 W	14.17 A
1800 W	15.00 A
1900 W	15.83 A
2000 W	16.67 A
2100 W	17.50 A
2200 W	18.33 A
2300 W	19.17 A
2400 W	20.00 A
2500 W	20.83 A
2600 W	21.67 A
2700 W	22.50 A
2800 W	23.33 A
2900 W	24.17 A
3000 W	25.00 A

At 240 Volts

Watts (W)	Amps (A)
100 W	0.42 A
200 W	0.83 A
300 W	1.25 A
400 W	1.67 A
500 W	2.08 A
600 W	2.50 A
700 W	2.92 A
800 W	3.33 A
900 W	3.75 A
1000 W	4.17 A
1100 W	4.58 A
1200 W	5.00 A
1300 W	5.42 A
1400 W	5.83 A
1500 W	6.25 A
1600 W	6.67 A
1700 W	7.08 A
1800 W	7.50 A
1900 W	7.92 A
2000 W	8.33 A
2100 W	8.75 A
2200 W	9.17 A
2300 W	9.58 A
2400 W	10.00 A
2500 W	10.42 A
2600 W	10.83 A
2700 W	11.25 A
2800 W	11.67 A
2900 W	12.08 A
3000 W	12.50 A

At 480 Volts

Watts (W)	Amps (A)
100 W	0.21 A
200 W	0.42 A
300 W	0.63 A
400 W	0.83 A
500 W	1.04 A
600 W	1.25 A
700 W	1.46 A
800 W	1.67 A
900 W	1.88 A
1000 W	2.08 A
1100 W	2.29 A
1200 W	2.50 A
1300 W	2.71 A
1400 W	2.92 A
1500 W	3.13 A
1600 W	3.33 A
1700 W	3.54 A
1800 W	3.75 A
1900 W	3.96 A
2000 W	4.17 A
2100 W	4.38 A
2200 W	4.58 A
2300 W	4.79 A
2400 W	5.00 A
2500 W	5.21 A
2600 W	5.42 A
2700 W	5.63 A
2800 W	5.83 A
2900 W	6.04 A
3000 W	6.25 A

Watts to Amps Conversion Formula

The formula for converting watts to amps depends on whether you’re dealing with direct current (DC) or alternating current (AC). Let’s explore both:

For DC Circuits:

I = P / V

Where:

• I = Current in amps (A)
• P = Power in watts (W)
• V = Voltage in volts (V)

A 12V DC motor consumes 24 watts. What’s the current draw?

I = 24W / 12V = 2A

For AC Circuits:

I = P / (V * PF)

Where:

• I = Current in amps (A)
• P = Power in watts (W)
• V = Voltage in volts (V)
• PF = Power factor (typically between 0.8 and 1)

1000W heater operates on 240V AC with a power factor of 0.95. What’s the current draw?

I = 1000W / (240V * 0.95) ≈ 4.39A

How Do You Convert Watts to Amps

• Determine the circuit type: Is it AC or DC?
• Gather the necessary information: You need to know the power (watts) and voltage (volts).
• For AC circuits, identify the power factor: If unknown, assume 1 for resistive loads or 0.8 for inductive loads.
• Apply the appropriate formula: Use I = P / V for DC or I = P / (V * PF) for AC.
• Perform the calculation: Divide watts by volts (and power factor for AC).
• Round the result: For practical applications, round to two decimal places.

Let’s convert 500 watts to amps for a 110V AC circuit with a power factor of 0.9.

Circuit type: AC

Power: 500W, Voltage: 110V

Power factor: 0.9

Formula: I = P / (V * PF)

Calculation: I = 500 / (110 * 0.9) = 5.05A

Rounded result: 5.05A

How Many Watts is 1 Amp?

• At 120V: 1A * 120V = 120W
• At 240V: 1A * 240V = 240W

The relationship between watts and amps depends on the voltage.

To determine how many watts 1 amp represents, we need to use the power formula:

P = I * V

Where:

• P = Power in watts (W)
• I = Current in amps (A)
• V = Voltage in volts (V)

How Many Amps is 1000 Watts?

• For a 120V circuit: I = P / V I = 1000W / 120V ≈ 8.33A
• For a 240V circuit: I = P / V I = 1000W / 240V ≈ 4.17A

To determine how many amps 1000 watts represents, we need to know the voltage of the circuit. Let’s consider two common household voltages:

This demonstrates that the same power (1000W) draws different amounts of current depending on the voltage. Higher voltage circuits require less current to deliver the same power, which is why many high-power appliances use 240V circuits.

How Many Amps is 1500 Watts?

• For a 120V circuit: I = P / V I = 1500W / 120V = 12.5A
• For a 240V circuit: I = P / V I = 1500W / 240V = 6.25A
• For a 277V circuit (common in commercial lighting): I = P / V I = 1500W / 277V ≈ 5.42A

Following the same principle as before, let’s calculate the current draw for 1500 watts at different voltages:

This comparison shows how higher voltages allow for lower current draw, which can be beneficial for energy efficiency and wire sizing in electrical systems.

How Many Amps is 7500 Watts at 120V?

To calculate the amperage for 7500 watts at 120 volts, we’ll use the watts to amps formula:

I = P / V
I = 7500W / 120V = 62.5A

This high amperage shows why 7500-watt devices are rarely connected to standard 120V circuits.

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