Calculating Square Footage

by Andrea Davis

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Calculating square footage and cubic footage of a house is important for current and prospective homeowners for many reasons. Finished and unfinished space can make a huge difference on a home's value and how much square footage you really get for the asking price. Here are a few factors to consider when measuring your home.

How to Calculate Square Footage

To determine square footage simply measure the length of the room and multiply by the width. That's it.

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Buying & Selling Square Footage

For real estate advertisings and listings, most agents determine square footage by measuring the exterior dimensions of the house.

To calculate square footage in this way, you would measure corner-to-corner or end-to-end. Then take the sum of the exterior length of the house and multiply by the sum of the exterior width. Real estate agents often measure straight corner-to-corner, then deduct non-heated spaces, and add heated spaces whose footprints exceed the end-to-end measurement.

Finished vs. Unfinished

When buying or selling, it's important to know which rooms count towards the total square footage and value of your house. The standard rule is that any rooms that are finished can count when calculating square footage and cubic footage of your home. Finished spaces are those that are heated and cooled in the way as the rest of the house. This means that, for example, if your enclosed porch is only heated with a space heater when the rest of the house is centrally heated, your porch cannot count towards total square footage. So, if you want to add more value to your home, you may consider adding central heating and cooling to your enclosed porch. This ensures the cost of your home reflects the most finished space possible.

Finished basements have their own set of rules, and even those can be subjective when calculating square footage and cubic footage. Typically, if the basement is heated and cooled in the same manner as the rest of the house, is carpeted or floored in the same way as the rest of the house, and has an entrance to the main floor it can count in your home's total dimensions. If it doesn't meet all three criteria, it may still be possible to state your basement square footage separately in a listing. If you're selling your house and have a basement, it's wise to consult with a real estate agent to determine if your basement should be included in the home's total measurements.


Whether or not you like the idea of renovating your house, know it can go a long way toward increasing your home's total value especially if you have a few unfinished spaces. If you sell, unfinished spaces do not count when calculating square footage and cubic footage of your home. If you want to be reimbursed for those spaces, it can be well worth the cost of finishing them. To qualify as finished, spaces must be carpeted or floored as well as heated and cooled. They must also directly attach to the main house. If you have a finished garage or pool house that is detached from the main living space, they may not count toward total square footage but can be listed separately.

Unfinished spaces are also important points of consideration for buyers. If you're willing to renovate them, you can dramatically add value to the home when it comes time to sell. Perhaps the house you're looking at only lists 1100 square feet, calculating square footage and cubic footage only for the main, finished living spaces. You may find when touring the home that it also has an attached, unfinished 800 square-foot basement. If you're willing to fix up the basement, you can get a great deal on the home. You'll get all of that space without actually paying for it.

If you have done any past expansions, it's important to factor in those additions when calculating square footage and cubic footage of your home. Buyers can also consider purchasing a home with smaller dimensions and then, if the property allows, adding on new space later to increase its value.

Growing Families

This may seem obvious; however, it is vastly important to factor in your family size when considering the dimensions of a new home. A two-bedroom house that measures in at 1200 square feet may be sufficient for you, your spouse, and perhaps a guest, but you may find yourself cramped for space if you plan to have children. Calculating square footage and cubic footage is important to ensure your new home allows for room to grow. Again, you may be able to look for homes with some unfinished spaces to make it easier on your wallet at the time of purchase. You can finish those spaces later to accommodate children as your family grows.

Renting Space

Just as it is important to know your home's square footage if you have a growing family, it's also important to know if you plan to rent any of your space out to tenants. If you plan to live on the same property with tenants, you'll need to ensure there is both enough space for you as well as the number of renters you expect to have. Calculating square footage and cubic footage of all of the living space as well as specific rooms in the home is imperative for anyone who is considering housing tenants. Unfinished spaces can come into play again in this situation. You can save money upfront and increase the home's value over time by adding renovated space to accommodate more tenants.

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Other Factors

There are a few other things to consider when comparing dimensions of homes or measuring your own. Furniture and decor are worth consideration because they can take up a large amount of floor and wall space. Calculating square footage and cubic footage is important in this situation to ensure the property doesn't just sound roomy, but that there really is enough physical floor and wall space to comfortably fit all of your furniture and decorations. For example, you might find a house listed at a spacious 2,000 square feet only to discover that most of that space comes from high walls and ceilings, leaving little floor space for furniture.

Whether you're buying or selling, these are a few reasons that calculating square footage and cubic footage is so important for current and prospective homeowners. Consult with a real estate agent to ensure you are getting the most value possible for your home.

Carpet Installation

Once you've determined the simple square footage of the room you're carpeting, you will need to add an extra 10 percent to your carpet order for cutting, waste, and staggering the carpet joints. A 10 x 10 room has 100 square feet. You would need to order 10% more or 110 square feet of carpet. Carpet installation generally requires padding that comes in 100 square foot rolls.