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How Many Solar Panels Can I Fit on My Roof? – Guide by Expert

Written by K. Miller / Fact checked by J. Fussell

how many solar panels can i fit on my roof

If you’re planning to switch to solar energy, you might be asking yourself “how many solar panels can I fit on my roof?” Fundamentally, an average solar panel system will need between 335 and 405 sq. ft. of roof space. If the space of your roof is meager, high-efficiency solar panels allow you to set up fewer modules while still covering your power requirements.

Should you wish to uncover more about choosing and installing solar panels on your roof, continue reading this post!

The Size of a Solar Panel

It’s essential to understand that solar panels are not designed with the same size. So, this means that you might require a different number of solar panels, depending on the model you pick.

Hence, you can determine the size of your solar array depending on the model and brand that you prefer to purchase. Keep in mind that you need to focus on what you are installing and the specific measurements. This is particularly true if you plan to set up the optimal number of solar panels on your roof.

In particular, the average solar panel measures 78.74 x 157.48 cm. You could utilize this to compute the number of panels your roof will hold approximately. In this computation, each panel takes up about 1.239-1.44 sq. m of space.

Hence, you can set up a maximum of 12 to 15 panels for a 19.72 sq. m of roof space. You need to round your number lower instead of higher if your computations do not result in a whole number.

The Importance of Sizing Your Solar Array


Installing solar panels at home or the workplace is indeed an excellent way to start saving more dollars on your energy bills. Nevertheless, it is essential to come up with an intelligent decision regarding your solar array. You’ll need to note the size, model, and brand of the solar panel you choose.

Selecting the appropriately-sized solar array can assist you in earning the most from your solar panels. This is because it guarantees that you’re getting the amount of energy you need.

In doing so, you obtain the perfect balance between your initial investment and your earnings in the long run.

What are the Factors that Help You Figure Out the Number of Solar Panels Needed

Many of us mistakenly think that the size of our house points out the number of solar panels we require. However, this is not the case. To unveil the number of solar panels your solar energy system requires, you must consider the following factors:

The amount of sunlight in your location and the inclination of the roof

Houses in locations that capture less sunlight will usually require more solar panels to reduce their energy bills than those in sunnier regions.

The installation surface must be well-inclined to provide an ideal angle of interaction between the system surface and the sunlight. This is why rooftops must possess the preferred inclination for the maximum operation of the solar panel systems.

Your energy consumption

You’ll require more solar panels to cover your energy costs if you consume more electricity.

Panel Wattage

The power rating of your solar panels demonstrates the amount of energy that they generate. The majority of solar panels installed nowadays come with a power rating of roughly 320 watts per panel.

Please note that fewer solar panels are required when installing panels designed with high wattage ratings.

How Many Solar Panels Can I Fit on My Roof


Computing the maximum size of an installation for your residence is a great initial step since it’ll provide you with a significant insight into what is and what’s not possible. Essentially, this computation includes the amount of money you’re willing to spend and the size of your roof.


Undoubtedly, the amount of money you’re willing to spend dramatically influences what you can and cannot purchase. With the cost of solar panels decreasing annually, going solar can be one of your wisest decisions.

The cost of installing solar panels commonly depends on several factors, such as your current state, your energy consumption, and your equipment’s brand.

Bear in mind that while bigger-sized solar systems are priced higher, they will help you save more bucks over time. If you require setting up a 10 kW solar system to satisfy all of your energy consumption, you might need to spend more. However, the delightful news is that this is a significant reduction in your utility bill monthly.

Presently, homeowners can refer to low-interest solar loans to make purchasing a solar panel system easier and expand their solar savings.

The Size of your Roof

Your roof size certainly affects your physical capability to set up your solar panels. Nonetheless, while it’s possible to begin with the optimal number of panels that will fit on your roof, consider going over your requirements and decide according to your budget.

Computing your roof size requires knowing your house’s measurements. To calculate, you can use a measuring tape to gauge along the bottom wall of your building. Alternatively, you may check the original blueprint of your house to obtain a general idea of your roof size or use a solar panel roof size calculator.

Note that you only need to measure the spaces that are appropriate for solar panels. For instance, if you prefer to set up solar panels on the south section of your house, measure the roof’s length along the south side. From there, you can measure the east side from the corner to the end of the roof — or, around 50% of your wall.

We strongly recommend installing the solar panels in an obstruction-free spot and on a south-facing roof with a 40-degree pitch.

If this is not feasible, you could still obtain money from panels assembled in other directions or on other roof types.

You only need to multiply the measurements of each wall to acquire the total size of your house. For example, if your south-facing roof measures 3.4 x 5.8 meters, you have a roof space amounting to 19.72 square meters.

Meanwhile, it’s helpful to check out this video to come up with an excellent decision regarding the number of solar panels you’ll need for your roof:

DIY or Professional Solar Panel System Installation

While there’s nothing wrong with having your solar panels installed on your own, it is still best to let a professional do the work. In truth, several things could go wrong if you’re not skilled or trained in the solar panel assembly process.

Some of the potential errors that could take place are:

Code Compliance and Safety Standards

The majority of solar panel warranties require an assembly process done by a licensed and trained professional. So, if you set up the solar system on your own, the warranties will become invalid.

As a result, in case there’s damage during the assembly process, or there’s an issue with the way the equipment was engineered, you’re unlikely to obtain any compensation.

What’s more, building permits and other accompanying regulations are complicated to follow if you’re not acquainted with them. It’s worth mentioning that you must complete all the paperwork correctly to avoid having the project rejected.

Cracked, Broken, or Leaky Roof

Setting up solar panels requires puncturing holes in your roof. So, if the holes are not made or sealed correctly, this can cause roof damage and leaks.

Issues with Wiring

Wiring is a type of task that calls for in-depth knowledge about electrical elements. If installed inappropriately, you could produce electricity shocks that are dangerous to you and everyone.

Hence, we strongly recommend that you consult an electrician to handle the electric work.


A home solar energy system could generate sufficient energy to satisfy your household needs. But, this will only happen if the PV solar system is sized correctly. As discussed, there are several factors to look into if you want to calculate solar system size.

How many solar panels can I fit on my roof? Again, to answer this question, you’ve got to take a closer look at the following factors:

  • Your budget and the size of your roof
  • Know your house’s measurements
  • Only measure the spaces appropriate for solar panels

Lastly, rather than working on the solar panel installation project yourself, letting a professional accomplish the job is safer and better.

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