Amps to Watts (A to W) Conversion Calculator

Use our calculator to easily convert amps to watts (A to W).

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watts
Formula: W = A × V
Formula: W = A × V × PF
Formula: W = A × V × PF × √3
Formula: W = A × V × PF × 3

Or would you rather convert watts to amps?

Amps to Watts Conversion Tables

Here are some tables converting amps to watts at common AC and DC voltages. All the AC conversion tables assume single-phase AC with a power factor of 1.

Amps to Watts at 5V (DC)

Amps (A)Volts (V)Watts (W)
1 A5 V5 W
2 A5 V10 W
3 A5 V15 W
4 A5 V20 W
5 A5 V25 W
6 A5 V30 W
7 A5 V35 W
8 A5 V40 W
9 A5 V45 W
10 A5 V50 W

Amps to Watts at 12V (DC)

Amps (A)Volts (V)Watts (W)
1 A12 V12 W
2 A12 V24 W
3 A12 V36 W
4 A12 V48 W
5 A12 V60 W
6 A12 V72 W
7 A12 V84 W
8 A12 V96 W
9 A12 V108 W
10 A12 V120 W

Amps to Watts at 24V (DC)

Amps (A)Volts (V)Watts (W)
1 A24 V24 W
2 A24 V48 W
3 A24 V72 W
4 A24 V96 W
5 A24 V120 W
6 A24 V144 W
7 A24 V168 W
8 A24 V192 W
9 A24 V216 W
10 A24 V240 W

Amps to Watts at 36V (DC)

Amps (A)Volts (V)Watts (W)
1 A36 V36 W
2 A36 V72 W
3 A36 V108 W
4 A36 V144 W
5 A36 V180 W
6 A36 V216 W
7 A36 V252 W
8 A36 V288 W
9 A36 V324 W
10 A36 V360 W

Amps to Watts at 48V (DC)

Amps (A)Volts (V)Watts (W)
1 A48 V48 W
2 A48 V96 W
3 A48 V144 W
4 A48 V192 W
5 A48 V240 W
6 A48 V288 W
7 A48 V336 W
8 A48 V384 W
9 A48 V432 W
10 A48 V480 W

Amps to Watts at 110V (AC)

Amps (A)Volts (V)Watts (W)
1 A110 V110 W
2 A110 V220 W
3 A110 V330 W
4 A110 V440 W
5 A110 V550 W
6 A110 V660 W
7 A110 V770 W
8 A110 V880 W
9 A110 V990 W
10 A110 V1100W

Amps to Watts at 120V (AC)

Amps (A)Volts (V)Watts (W)
1 A120 V120 W
2 A120 V240 W
3 A120 V360 W
4 A120 V480 W
5 A120 V600 W
6 A120 V720 W
7 A120 V840 W
8 A120 V960 W
9 A120 V1080 W
10 A120 V1200 W

Amps to Watts at 220V (AC)

Amps (A)Volts (V)Watts (W)
1 A220 V220 W
2 A220 V440 W
3 A220 V660 W
4 A220 V880 W
5 A220 V1100 W
6 A220 V1320 W
7 A220 V1540 W
8 A220 V1760 W
9 A220 V1980 W
10 A220 V2200 W

Amps to Watts at 230V (AC)

Amps (A)Volts (V)Watts (W)
1 A230 V230 W
2 A230 V460 W
3 A230 V690 W
4 A230 V920 W
5 A230 V1150 W
6 A230 V1380 W
7 A230 V1610 W
8 A230 V1840 W
9 A230 V2070 W
10 A230 V2300 W

Amps to Watts at 240V (AC)

Amps (A)Volts (V)Watts (W)
1 A240 V240 W
2 A240 V480 W
3 A240 V720 W
4 A240 V960 W
5 A240 V1200 W
6 A240 V1440 W
7 A240 V1680 W
8 A240 V1920 W
9 A240 V2160 W
10 A240 V2400 W

Converting Amps to Watts in AC vs DC Circuits

Converting amps to watts is different depending on whether you're working with direct current (DC) or alternating current (AC).

AC power is used in our modern electrical grid, as this type of electricity is easy to transmit over long distances without losses. The majority of the appliances in your home run on AC power.

DC power, on the other hand, is produced by things like batteries, fuel cells, and solar panels. The phone, tablet or laptop you are reading this on uses DC power, as these devices rely on batteries to operate.

Tip: If you're ever unsure if a device uses AC or DC, look for the following symbols: a dotted line with a solid line above it (⎓) signifies DC, while a wavy line, or tilde (~) signifies AC. You can see these symbols in the following picture of my multimeter.

This multimeter is set to the DC voltage setting, as indicated by a "V" with the direct current symbol (⎓) next to it. You can see also see the AC voltage setting above it, as indicated by a "V" with the alternating current symbol (~). The current settings on the right have a wavy line with a solid line above it, indicating that those settings can measure both AC and DC current.

How to Convert Amps to Watts for DC Circuits

To convert amps to watts in a DC circuit, simply multiply amps by volts.

Conversion formula: watts = amps × volts

Abbreviated formula: W = A × V

You'll often see this formula written slightly differently, with amps abbreviated as I instead of A and watts abbreviated as P instead of W. The formula itself remains the same, only the abbreviated version changes.

Alternate abbreviation: P = I × V

Note: This formula is sometimes called the electrical power formula, which simply states that power equals current times voltage.

Example: DC Circuit

I have the following solar panel with a rated output of 5.41 amps at 18.5 volts.

With these specs, here's how you calculate the panel's max power output in watts:

5.41 A × 18.5 V = 100.085 W

So my panel is a 100 watt solar panel.

How to Convert Amps to Watts for Single-Phase AC Circuits

To convert amps to watts in a single-phase AC circuit, multiply by watts and then by the power factor.

Conversion formula: watts = amps × volts × power factor

Abbreviated formula: W = A × V × PF

Alternate abbreviation: P = I × V × PF

Example: Single-Phase AC Circuit

Let's say you're trying to calculate how many watts your phone charger uses. You squint at its electrical specifications and see it outputs 0.7 amps at 100-240 volts.

To figure out which voltage to use, you need to know your country's residential voltage, often called the mains voltage. Let's assume you live in the US, where the voltage of standard wall outlets is 120 volts AC.

So we have our amperage (0.7 A) and our voltage (120 V). But, because we're dealing with an AC circuit, we still need the power factor.

The power factor is a number between 0 and 1. There are some online resources that give rule-of-thumb power factors based on device type, but to find the exact power factor of a circuit, you need some equipment. I used an electricity usage monitor called a Kill-a-Watt to help me find it for this phone charger. It turned out to be 0.5.

Now we have all the numbers we need to calculate the phone charger's wattage:

0.7 A × 120 V × 0.5 = 42 W

It turns out your phone charger uses up to 42 watts.

If you're perceptive, you probably noticed that the output of the charger is 4.8 amps at 5 volts DC (these values are also listed on the device in the picture above). That means the max output of the charger is 24 watts (4.8 A × 5 V = 24 W). So the charger operates at around 57% efficiency (24 W ÷ 42 W ≈ 57%).

How to Convert Amps to Watts for Three-Phase AC Circuits

The formula for calculating watts for a three-phase AC circuit depends on whether it's line to line or line to neutral voltage.

Using Line to Line Voltage

To convert amps to watts for a three-phases AC circuit using line to line voltage, multiply amps by volts by the power factor by the square root of 3.

Conversion formula: watts = amps × volts × power factor × √3

Abbreviated formula: W = A × V × PF × √3

Alternate abbreviation: P = I × V × PF × √3

Using Line to Neutral Voltage

To convert amps to watts for a three-phases AC circuit using line to neutral voltage, multiply amps by volts by the power factor by 3.

Conversion formula: watts = amps × volts × power factor × 3

Abbreviated formula: W = A × V × PF × 3

Alternate abbreviation: P = I × V × PF × 3

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Alex Beale
Alex Beale is the founder and owner of Footprint Hero. As a self-taught DIY solar enthusiast, Alex has spent 4 years producing educational solar content across YouTube, TikTok, Instagram, and the Footprint Hero blog. During that time, he's built Footprint Hero to over 7 million blog visits and 18 million YouTube views. He lives in Tennessee.