# Calculating Square Footage and Cubic Footage

by Paul Aertker

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Two Criteria

All real estate boils down two main criteria: location and square footage. While you can rarely change a house's physical location, you can change its actual square footage.

There are two great ways to make a house look and feel bigger. Expanding a kitchen or family room is the most obvious way to add to a home's physical size and feel. What is more, additions and remodels that convert attics, basements, porches, or garages into useable (and heated) space creates more square footage, increases a home's value, and reduces the cost per square footage price to prospective buyers.

Easy Math
To determine square footage simply measure the length of the room and multiply by the width. That's it. Real estate square footage is calculated differently (see next section), while establishing square footage for carpet installation requires an additional step.

Simple Square Footage Calculator

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.

For real estate advertising 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.

Which Rooms Can Be Included And Excluded?
An enclosed porch that is heated or cooled in a way similar to the rest of the house (no space heaters) is considered part of the overall calculation. Square footage also includes stairways that are finished like the rest of the house. (You can't paint your basement steps and add that footage to the overall number.) Closets, walk-in pantries, and mechanical rooms (water heater, furnace) on the main floor or higher are typically included in total square footage calculations. Additionally, living areas of completely finished walkout basements that have outside access can be included in total square footage.

A furnace room in the basement and garages are always excluded from square foot calculations. Basements that lack ingress and/or egress to a ground floor are also not included. Square footage for basements that lack egress is generally listed as a separate number. A licensed real estate agent can tell you if your basement legally qualifies to be included in the calculation.