House Amp Calculator: How to & What They’re for -
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House Amp Calculator

Short on Time? Here’s The Article Summary

This article explains how to use a house amp calculator to determine the electrical amperage needs of a home. It describes amperage as the measurement of electricity flow through home wires, with older homes typically needing lower amperage and modern homes requiring higher amperage due to more advanced technology.

The article outlines the amperage needs for different types of homes and provides a formula for calculating the total amperage of a house based on the appliances and circuits. It also discusses the importance of not overloading inverters in solar power setups, as they have a maximum amperage capacity. The article concludes by offering resources and assistance for setting up solar power systems.


A house amp calculator will help you understand how many amps your house requires. 

Amperage is the measurement of the flow of electricity through the wires in your home. This means it measures the pressure of the electricity moving through your home’s wires.

Older homes have a lower amperage, and more modern homes have a higher amperage. This is because the newer a home is, the more sophisticated the wiring and heating system will be.

How Many Amps do I Need in My House?

amp calculator for house

As we mentioned, different homes have different amperage needs. If your home is older, it will generally have lower amperage needs because there isn’t as much high-tech equipment to power.

These homes typically require around 30 amps of pressure.

Newer homes have more technology and appliances to power, so the pressure of the electricity moving through the wires needs to be higher. In general, these homes require between 100 and 200 amps of pressure.

It can vary though, and this is why it’s useful to know how to calculate the needs of your particular home.

If you’re looking to convert to solar power, have a look at our complete solar panel kits. They contain everything you need, and none of these calculations will be necessary.

Home Amp Calculator

Calculating the amperage of your home requires the use of a simple formula. The kicker is, your home is made up of a few circuits. 

You can calculate the amperage of each circuit in your home and then add those together. So while the formula is super easy to use, you need to remember to use it for all the circuits in your home and add those values together for an accurate result. 

We’ll do our calculations based on certain appliances being used. If you have other appliances plugged in, you’ll need to use the wattage and voltage values attached to those appliances. 

You also need to take your inverter amp draw into account when working this out.

how many amps do i need in my house calculator

You simply plug the values into the formula, punch them into your calculator, and you’ll have your answer.

Doing the Math

The Watt’s Law formula is as follows: 

A = Watts / Volts 

We’ll assume you have a lightbulb plugged into one of your circuits and use the wattage and voltage of the bulb to determine the amperage it is pulling.

The average lightbulb uses 25W of power and 110V.

So, let’s plug those values in:

A = Watts / Volts

   = 25 / 110

   = 0,22A. 

This illustration has been simplified to help you understand the equation, but you likely have much more than one lightbulb plugged into the same circuit in your home. 

home amp calculator

You might have your refrigerator, stove, dishwasher, and lightbulb running off the same circuit. 

You’d simply need to find the wattage of each appliance and add those values together, followed by the voltage of each appliance and adding those values together.

It could look something like this:

  • Refrigerator: 500W; 220V
  • Stove: 1,000W; 220V
  • Dishwasher: 1,200W; 120V
  • Lightbulb: 25W; 110V.

You’d add these values together, and plug them into the formula.

A = Watts / Volts

   = 2725 / 670

   = 4,06A.

This is the amperage being pulled from one circuit in your home, and you’d need to repeat this per circuit in your home. Add the answer you get from each circuit, and that will give you the amperage load of your entire home.

Bear in mind that some appliances list their power draw under different orders of magnitude. This is why it’s important to be able to convert mAh to Ah.

But why would you need to do this? And how does it apply to you as a solar power user? We’ll explain below. 

How Does This Affect My Solar Setup?

residential amp calculator

As a solar power user, you’ll have an inverter installed somewhere in your home. Your most important priority should always be to never overload your inverter.

In fact, you should never use it at above 80% of its amperage capacity. Don’t get this confused with battery capacity, as that should never go below 50% power level.

Your inverter pulls amps from the battery inside it, which is what stores the power you’ve harnessed from the sun.

It’s important to note that your inverter pulls power from the battery even when nothing is plugged into it and drawing power. This will be between 0.2 and 2 amps per day, and you’ll need to take this into consideration when figuring out how much load you can take from your inverter in terms of amperage. 

home electrical amp calculator

If your inverter has a 2,000W capacity and a voltage of 12V, its amperage will be around 166A. 

You’ll need to make sure that all the appliances you plug into your inverter used together don’t use more than 80% of that amperage. That means they can’t use more than 132,8A. 

We want to make solar simple and accessible so that more people harness the power of the sun and use sustainable energy sources. 

To this end, we’ve put together other resources to help you out. You can look at our volts to amps calculator, kVa to amps calculator,  and our mWh to kWh calculator.

If you’re struggling with your solar setup, or need help choosing components for a new setup, feel free to give us a call at any time. We’d love to help!

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Article by

Alex S

Alex is a co-founder of Shop Solar, a company that he established in 2018 to revolutionize the solar industry by simplifying the process and making it more simple and cost-effective. Under his strategic leadership, Shop Solar has grown into a comprehensive one-stop-shop, empowering over 40,000+ customers to access top-quality solar and storage solutions, comprehensive information, intuitive tools, and professional installation services.

With a passion for innovation and sustainable energy, Alex has successfully expanded the business's reach and impact, serving as a driving force in the company's growth and development. You can browse best seller's here.

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