Amps to Watts Electrical Conversion Calculator

Enter the current and voltage to convert amps to watts for DC and AC single and three-phase circuits.

Try our watts to amps calculator.

How to Convert Amps to Watts

Converting amps to watts can be done using the power formula, which states that I = P ÷ E, where P is power measured in watts, I is current measured in amps, and E is voltage measured in volts.

Using a little algebra it’s possible express the amps to watts formula as:

P_(W) = I_(A) × V_(V)

Thus, the power P in watts is equal to the current I in amps multiplied by the voltage V in volts.

Single-Phase AC Circuit Amps to Watts Conversion

Converting amps to watts for a single-phase AC circuit with power factor requires a slight variation of the formula.

P_(W) = I_(A) × V_(V) × PF

The power P in watts is equal to the current I in amps multiplied by the voltage V in volts multiplied by the power factor PF. We suggest using a power factor calculator to find the PF value.

Three-Phase AC Circuit Amps to Watts Conversion

Using Line to Line Voltage

For three-phase AC circuits where the line to line voltage is known, the formula to convert amps to watts is:

P_(W) = I_(A) × V_(V) × PF × √3

The power P in watts is equal to the current I in amps multiplied by the voltage V in volts multiplied by the power factor PF multiplied by the square root of 3.

Using Line to Neutral Voltage

For three-phase AC circuits where the line to neutral voltage is known, the formula to convert amps to watts is:

P_(W) = I_(A) × V_(V) × PF × 3

The power P in watts is equal to the current I in amps multiplied by the voltage V in volts multiplied by the power factor PF multiplied by 3.

How to Convert Amps and Ohms to Watts

You can also convert amps to watts using circuit resistance with this formula:

P_(W) = I_(A)² × R_(Ω)

The power P in watts is equal to the current I in amps squared multiplied by the resistance R in ohms.

Since 1 kilowatt is equal to 1,000 watts, it is possible to use the formulas above to also convert amps to kW, but the result will need to be divided by 1,000. You can also use our amps to kW calculator to solve for kilowatts.

Equivalent Amps and Watts at 120V AC

Equivalent ampere and watt values at 120 volts.

Current	Power	Voltage
1 Amps	120 Watts	120 Volts
2 Amps	240 Watts	120 Volts
3 Amps	360 Watts	120 Volts
4 Amps	480 Watts	120 Volts
5 Amps	600 Watts	120 Volts
6 Amps	720 Watts	120 Volts
7 Amps	840 Watts	120 Volts
8 Amps	960 Watts	120 Volts
9 Amps	1,080 Watts	120 Volts
10 Amps	1,200 Watts	120 Volts
11 Amps	1,320 Watts	120 Volts
12 Amps	1,440 Watts	120 Volts
13 Amps	1,560 Watts	120 Volts
14 Amps	1,680 Watts	120 Volts
15 Amps	1,800 Watts	120 Volts
20 Amps	2,400 Watts	120 Volts
25 Amps	3,000 Watts	120 Volts
30 Amps	3,600 Watts	120 Volts
35 Amps	4,200 Watts	120 Volts
40 Amps	4,800 Watts	120 Volts
45 Amps	5,400 Watts	120 Volts
50 Amps	6,000 Watts	120 Volts
60 Amps	7,200 Watts	120 Volts
70 Amps	8,400 Watts	120 Volts
80 Amps	9,600 Watts	120 Volts
90 Amps	10,800 Watts	120 Volts
100 Amps	12,000 Watts	120 Volts

Equivalent Amps and Watts at 12V AC

Equivalent ampere and watt values at 12 volts.

Current	Power	Voltage
1 Amps	12 Watts	12 Volts
2 Amps	24 Watts	12 Volts
3 Amps	36 Watts	12 Volts
4 Amps	48 Watts	12 Volts
5 Amps	60 Watts	12 Volts
6 Amps	72 Watts	12 Volts
7 Amps	84 Watts	12 Volts
8 Amps	96 Watts	12 Volts
9 Amps	108 Watts	12 Volts
10 Amps	120 Watts	12 Volts
11 Amps	132 Watts	12 Volts
12 Amps	144 Watts	12 Volts
13 Amps	156 Watts	12 Volts
14 Amps	168 Watts	12 Volts
15 Amps	180 Watts	12 Volts
20 Amps	240 Watts	12 Volts
25 Amps	300 Watts	12 Volts
30 Amps	360 Watts	12 Volts
35 Amps	420 Watts	12 Volts
40 Amps	480 Watts	12 Volts
45 Amps	540 Watts	12 Volts
50 Amps	600 Watts	12 Volts
60 Amps	720 Watts	12 Volts
70 Amps	840 Watts	12 Volts
80 Amps	960 Watts	12 Volts
90 Amps	1,080 Watts	12 Volts
100 Amps	1,200 Watts	12 Volts