Watts to Amps Calculator - ShopSolar.com
Skip to content
Cart (0 item)

Your cart is empty

Watts to Amps Calculator

A basic watts to amps calculator uses the equation explained in Watt’s Law. Both watts and amps are units used for measuring a form of electricity. 

Watts specifically measure power, while amps measure current.

Watts can’t directly be converted to amps since it’s not a one-to-one comparison, but we’re going to simplify the math for you. 

The calculation isn’t difficult to do when you understand the various steps involved and have a handy watts to amps calculator by your side.

Watts to Amps Calculator



How to Convert Watts to Amps

watts to amps calculator

Watt’s Law states that power is equal to the voltage multiplied by the current. This is denoted as P = VI. Watts are represented by P in this formula, which stands for power. 

Amps are represented by I, which stands for current when doing electrical calculations. You’d therefore need the voltage to be able to complete your calculation.

To put the calculation into simpler terms, this is the formula you’d be using for the watts-to-amps conversion: Watts = voltage x current.

Below, we’ll take you through an example to illustrate how easy this formula is to use. 

Amp Calculator Example

Here’s an example of what it looks like when you use the formula, so you can see how simple it is to work out current.

Let’s say you have a power value of 4,160 Watts and a voltage of 208 Volts. You simply need to plug these values into the formula, and you can find the amps or current. 

The problem, though, is that the formula is built around finding out the Wattage. The answer is restructuring the formula to find the variable you’re missing.

It’ll look like this: 

I = P / V. 

In other words, current = power/voltage.

See, easy! Your calculation would therefore be:

Current = 4,160 / 208. The answer is therefore 20 Amps.


convert watts to amps

But what if you already know the current, but you’re trying to figure out the wattage. Well, it’s pretty easy. All you need to do is some basic algebra.

Doing this, you end up with P = I x V.

To prove this, let’s work backwards from the previous example. Assuming we know that the current is 20 Amps and the voltage is 208, our equation looks like this:

P (Watts) = 20 X 208 = 4,160 

Why Do This?

Knowing the current flowing from your solar power system can help you figure out how many appliances it can power. You can also use this unit to calculate how much power your home uses, which can help you figure out how much money you’ll be able to save if you install a solar power system.

If you want to do the calculation the other way around and figure out the Wattage your system produces, check out our guide on the watt calculator. We also have an easy-to-understand volt-to-watt conversion calculator.

If you're using a generator, you can check out our watt calculator for generators.

The output rating of a solar panel is measured in Watts. If you’re looking for the figures to complete the “watt to amps” conversion, you should be able to find this either on the packaging of your solar panel or on the solar panel itself.

The wattage differs between solar panel models but is usually in the range of 275 and 400 DC Watts per panel. When installing panels, you’ll also need an inverter.

Your panels will trap the sun’s energy and turn it into electricity, but the inverter is what stores that energy. This allows you to use it outside of daylight hours.

Convert 1,500 Watts to Amps

As another example, we’re going to show you how to convert 1,500 Watts to Amps. While this might seem like an unreasonably large number, once you convert watts to kilowatts, it’s actually pretty manageable.

As mentioned earlier, you need to rearrange the formula to focus on the variable you want to find out. So, we’ll use the formula I = P / V, or current = power/voltage.

For the calculation, we’ll use the average voltage of a solar panel, which is 17V. 

Current = 1,500 / 17.

The current is therefore 88.24A.

Watts to Amps 12V Calculator

We can do the same calculation with a lower voltage, as some solar panel systems do have a lower voltage. 

It’ll look like this: current = 1,500 / 12.

Your answer would be 125A.

We know that all of these calculations can get confusing, and that’s why we’ve made it our mission to make solar simple. People commonly need to do these equations when figuring out what inverter they should buy to power their homes.

Here are some useful tips to consider:

  • The voltage of your inverter should always match the voltage of your battery pack;
  • It’s best to get an inverter with a wattage higher than what you’d need to power your house so that you never deplete it;
  • Check the surge capacity of the inverter and compare it to the surge kick of your appliances to make sure they’re compatible;
  • Determine whether you need a single or split-phase output to power your appliances.

We stock a variety of inverters to meet all needs. Whether you want a small setup to power a few appliances in your RV or want to take your home or office fully off-grid, we can assist. 

We carry only the best brands in the business and all our stock ships from one of our five warehouses located around the US. This way, we can ensure your inverter gets to you as quickly as possible. We know you must be eager to get it set up.

If any of this information feels too confusing or overwhelming, give us a call at 877-564-8231. We’re always happy to help you make the switch to solar!

You can also make use of our solar load calculator to determine your needs.

You can find all of the solar & electrical calculators we have created in order to help you plan, size and install your own solar power system here.

The Ultimate Solar + Storage Blueprint (Mini Course)

Struggling to understand how solar + storage systems actually work? Looking to build or buy your own solar power system one day but not sure what you need? Just looking to learn more about solar, batteries and electricity?

Join 15,000+ solar enthusiasts breaking free from their energy dependence with this short step-by-step video course that will make you a solar + storage expert. Start your journey to energy independence today.

Learn More Now

Who is ShopSolar.com?

ShopSolar.com is the #1 digital platform that enables consumers & businesses to source and purchase complete solar + storage solutions direct, saving you thousands in time, energy and money! With over 40,000+ happy customers, we’re on a mission to make solar simple, transparent and affordable.


Did You Find Our Blog Helpful? Then Consider Checking:

Get a Complimentary Solar Proposal Today!

$150 Value - Free Offer (Limited Time Only!) No Strings Attached. Totally Free. Takes Less than 2 Minutes.

Get Started