Convert Amps To Watts (A to W): Simplest Calculator + Conversion Chart

Amperes (A), volts (V), and watts (W) are the 3 basic electrical units, connecting electrical current, voltage, and power. Every electric device – from air conditioners to washing machines and generators – includes them in their specification sheets.

One of the most common questions here is this: How to convert amps to watts?

To convert amps to watts, we need to use the following formula for electrical power:

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

In a simple equation, here’s the relation:

Watts = Amps * Volts

To calculate watts, we need both the amperage and voltage (usually either 120V or 220V).

LearnMetrics has prepared handy amps to watts calculator you can freely use. Below the A to W calculator you will also find a table with calculated watts from amps for 120V and 220V voltage systems. To illustrate how amps to watts calculation works, we have also solved 3 examples (scroll down).

Amps To Watts Calculator

How Many Amps Are In A Watt?

For easier calculations, knowing how many amps are in a watt is very useful. We start with the original formula for electrical power:

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

To calculate how many amps are in a watt, we need to specify the voltage. Let’s take the basic 120V. Here’s how we calculate the number of watts in a single amp:

P (W) = 1 A * 120 V = 120 W

As we can see, at 120V, 1 amp is equal to 120 W.

If we use the 220V voltage, we have this amps to watts equation:

P (W) = 1 A * 220 V = 220 W

At 220V, 1 amp is equal to 220 watts.

Here is a full amps-to-watts conversion chart, with solved examples below:

Amps To Watts Conversion Chart

This is chart is quite easy to use. For example, how many watts is 50 amps? Just consult the chart and you can see that at 120V 50 amps is 6,000 watts and at 220V 50 amps is 11,000 watts.

Let’s solve some real-life examples:

3 Amps To Watts (Example 1)

Let’s say that we have a 5000 BTU portable air conditioner. This is considered a very small air conditioner; it’s powered by only 3 amps.

How many watts does a 3 amp air conditioner use? It’s connected to 120V and we can use the upper amps to watts calculator to figure this out, like this:

In short, 3 amps is 360 watts.

15 Amps To Watts (Example 2)

More powerful units, like washing machines and mini-split air conditioners, can be powered by 15 amps. How many watts is that?

Here’s the calculation of 15 amps to watts at 120V:

15 amps are equal to 1800 watts at 120.

If the voltage would be 220V, 15 amps would equal to 3300 W.

100 Amps To Watts (Example 3)

More powerful electrical units can draw as much as 100 amps. For these units, you already need amp breakers. 5 zone mini-split units are a good example of 100 amps electric devices.

They are hooked up to 220V because 120V would need even more current. Here’s the conversion of 100 amps to watts:

This is a massive 22,000 W device at 100 amps.

If you have a specific example in mind, you can post it in the comments below and we’ll solve it together.