kWh Per Square Foot Calculator (Simple Guide For Your Solar Needs) -
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kWh Per Square Foot Calculator

It can be challenging to work out precise solar measures, especially when it comes to how many kWh are needed per square foot.

If you’re new to the solar scene, you might struggle with these calculations because of the intricacy, The truth is that they’re a lot easier than they first appear. 

The problem is that newbies aren’t given the right advice to make these calculations simpler.

Determining the electricity consumption of your home following its size makes it easier to decide on the type of solar panel system that needs to be installed to meet your electrical needs.

We want to take you through all the steps you need to work out the energy (kWh) you can produce depending on the size of your system. We also cover the considerations to think about to ensure you’re getting the most out of your solar system.

If you want to utilize other effective solar calculators such as a kilowatt per hour calculator, kW to amps calculator, or even a kW to kWh calculator, we have plenty of resources on those topics too. You never have to feel lost again using our resources as a guide.

Adding Up Your Energy Consumption

kwh per sq ft calculator

Typically, the kWh per square foot your system can produce changes constantly depending on the time of year, since the energy captured from the sun changes in different seasons. Either way, the best place to start is to figure out how much power you need to produce to cover all of your appliances.

You don’t necessarily need to produce 100% of the energy you use through solar power. Even a marginal percentage is enough to make a drastic difference to your energy bill at the end of each month.

Calculating kWh isn’t as simple as measuring the size of your home. You need to add up all the appliances in your home and their respective power consumption.

For instance, a refrigerator uses about 2 kWh per day, a stove uses around 3.5 kWh per day, and a TV uses around 0.1 kWh. To work this out, there a relatively simple equation that you can use.

Energy Consumption Calculation

To work out the kWh consumption of your various appliances, you need to find what their power-draw is when turned on. This is usually written on the side or back of the appliance and is given in watts. 

For this example, we’ll use a washing machine for the values. 

kilowatt-hour per square foot calculator

The average washing machine uses around 500 W when running. Assuming that it runs for half an hour, our equation will look like this:

kWh = (Watts / 1,000) x Time (hours)

kWh = (500 / 1,000) x 0.5

kWh = 0.25

This means that a washing machine uses 0.25 kWh each time you use it. Assuming you use a washing machine once a day, the total monthly consumption will be 7.5 kWh.

From here, you should figure out how much energy your household uses over 12 months. This will cover all the seasons and the fluctuations in energy usage giving you a more accurate reading.

To make it easier, create a list for yourself and tally up the kWh units you used over the year by using an old utility bill statement or any other pre-paid electricity receipt.

If not, call your electricity provider. They should be able to tell you how many kWh, or "units," you consumed over the previous 12 months.

To give you a rough idea, an average home in a fairly sunny area uses about 1,200 kWh per month.

The Size of Your Home

Once we’ve added up the total kWh for each appliance in our home, we then need to calculate the total usable space in your home in square feet.

energy consumption per square foot calculator

When measuring your usable space you shouldn’t take into account your garage, storage spaces, and outside areas. You need to consider which areas in your home can support solar panels. 

Typically, the best place to start is on your roof since it’s generally going to be clear of any shade or obstructions, but other areas work too. If you have a large yard that gets lots of sun, consider using some of it for your solar panel setup.

The Final Calculation

Now that we have both our total kWh and the total size of our home in square feet, we can begin the final calculation which is the simplest one of them all and the least time-consuming.

All you have to do for this step is take your total kWh for the year, you can also do this for a single month, and divide it by the total square feet of your home.

To put it all into perspective, let’s say you measured your yearly energy usage, and it came to a total of 1,185 kWh. You then measured your usable solar space, and it came to a total area of 3,000 square feet.

All you have to do to determine your kWh per square foot reading is divide your total energy, in this case, 1,185 kWh, by the total solar-ready area, which we measured to be 3,000 square feet. This gives us a final reading of 0.395 kWh per square foot.

This is a great way to figure out how many solar panels you need and how efficient they need to be. The better your solar panels are, the less space in your home you’ll need to dedicate to energy production.

For the 0.395 kWh per square foot reading, we calculated previously, we need about 30 solar panels to meet our electrical needs. You can also incorporate this reading into your kilowatt-hour cost calculator to give you a more precise reading. 


As you can see, once you know your way around, it’s easy to calculate kWh per square foot. 

kwh per square foot estimate

It can be a lengthy process, but once you have the right metrics from measurements to energy usage, you can easily calculate the kWh per square foot reading.

Our easy-to-follow guide doesn’t have any overcomplicated math and primarily relies on practical measurements that you can easily find to perform the final calculation.

If you’re still a little confused after reading this guide, reach out to Shop Solar Kits for any additional assistance. Not only do we offer 5-star customer service, but we also have an incredible range of solar products which include the powerful EP500 Bluetti.

You now know everything about kWh per square foot calculations and the steps you have to take to calculate an accurate reading.  Perhaps you can try your hand at converting kWh to amps now that you’re an expert.

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