How To Calculate Square Footage of a Room

Reader Success Stories

  • Monica Williams

Nov 6, 2016

    Monica Williams Nov 6, 2016

    “This article and video showed me how to calculate the square footage of my space. I’m planing to tile my living room (rectangle) and saw at Costco a beautiful tile. The box said it covers almost 10 square feet. Now I will measure my living room and see how many boxes I need. Thank you.” …” more

More reader stories Hide reader stories Share your story

How to Calculate Square Footage

Square footage is area expressed in square feet. Likewise, square yardage is area expressed in square yards.  Square meters is also a common measure of area.

Assume you have a rectangular area such as a room and, for example, you want to calculate the square footage area for flooring or carpet.

The way to calculate a rectangular area is by measuring the length and width of your area then multiplying those two numbers together to get the area in feet squared (ft2). If you have on oddly shaped area, such as an L-shape, split it into square or rectanglualar sections and treat them as two separate areas. Calculate the area of each section then add them together for your total. If your measurements are in different units, say feet and inches, you can first convert those values to feet, then multiply them together to get the square footage of the area.

Convert all of your measurements to feet

  • If you measured in feet skip to “Calculate the Area as Square Footage”
  • If you measured in feet & inches, divide inches by 12 and add that to your feet measure to get total feet
  • If you measured in another unit of measure, do the following to convert to feet – inches: divide by 12 and that is your measurement in feet – yards: multiply by 3 and that is your measurement in feet – centimeters: multiply by 0.03281 to convert to feet – meters: multiply by 3.281 to convert to feet

Calculate the Area as Square Footage

  • If you are measuring a square or rectangle area, multiply length times width; Length x Width = Area.
  • For other area shapes, see formulas below to calculate Area (ft2) = Square Footage.


How much to allow for waste?

To allow for waste, you must consider the installation.  For most standard installations, 10% extra for waste is sufficient.  Percentage of waste for more elaborate patterns like running tile on a 45 degree angle, herringbone or cross hatch, consult with your installer. Add 15% for tile being installed in a room with lots of jogs and corners. These installations will require more cuts and thus more waste.

Length x Width + Waste = Amount Needed

The importance of knowing square footage

What’s the big deal about square footage, anyway? Why is it so hard to calculate — and so important to know?

Square footage is a necessary piece of data for determining a number of things about your home and your family’s needs. These are just some of the reasons it’s so important to know and understand square footage.

Home value and price per square foot

First and foremost, square footage is a major factor in determining your home’s value. Generally, when appraising a home, professionals will first calculate the exact square footage, and then compare your home to other homes in the same area with a comparable amount of living space.

They’ll make adjustments based on factors like your home’s age, materials, and finishes — but square footage is the single most important factor (and the first step) in setting a value or sale price for your home. Additionally, being familiar with the price per square foot for your home and similar, nearby listings can give you a point of reference for comparing different properties when shopping for a home.

This is also one of the reasons it’s so important to get an accurate measurement of your home’s square footage — if it’s measured incorrectly, that can have a domino effect that throws off your home’s value, sale price, and more.

Home renovation costs

If you ever make any major updates to your home — for example, renovating your kitchen or finishing your basement — you’ll likely need to know the exact square footage in order to get building permits.

Knowing the exact square footage of a space you’re renovating is also helpful when it comes to making cost estimations and setting a budget for the project. Different areas, like kitchens, bathrooms, and basements, have different average costs per square foot to renovate, so familiarizing yourself with these can help you set a realistic budget for making over your own space.

Property taxes

Since square footage is such an important factor in your home’s value, it’s also a big part of determining your yearly property taxes, which are based on the assessed value of the home and property. If your square footage is improperly calculated, it could result in you over- or under-paying on your taxes.

Additionally, if you work from home, knowing your home’s square footage can help provide tax benefits — you may be able to write off a portion of your rent or mortgage payments and utilities based on the square footage of a home office or work area.

Knowing your (and your family’s) needs

Finally, knowing and understanding square footage can help you better understand exactly what your family needs when looking for a home. We’ll get into this in more detail below, but it’s always a good idea to know how much square footage your family needs to live and function comfortably.

When in doubt, ask the pros

If calculating the square feet of your particular property feels overwhelming, consider hiring a professional appraiser to do it. The average appraisal cost for a single-family home typically runs about $350. A condo appraisal fee is generally between $300 and $500, and multi-family home appraisals can run anywhere from $600 to $1,500.

While two different professional appraisers could evaluate the same home and come up with slightly different square footage figures, they do all aim for scientific accuracy. “We’re always shooting for somewhere between 1 to 3 percent variance,” Day says.

How to find the square footage of a triangle

  1. Measure the length of the base and the height of the triangle in feet.
  2. Multiply your base and height measurements together.
  3. Divide your total by two to get the square footage of the triangle
 The formula for calculating the square footage ar

The formula for calculating the square footage area of a triangle is: base × height / 2. To work out your cost of materials, simply multiply this figure by your 'price per square foot'.

How to calculate square footage pricing

Once again, we tackle a widespread issue that, despite the complications which might arise in real life, has some rather simple maths beneath it. The calculations of square footage pricing are, mathematically, the simple division of the price of a specific property by its total square footage. In everyday life, this value changes significantly depending on such factors as a location of the property, intended or potential use, and so on. It is nonetheless a useful quantity to evaluate the value of a particular house or property.

  Before we talk a bit more about the usefulness of this measurement, let’s take a look at how we can use this calculator when square footage pricing comes into play. First, make sure that the “One room/area” option is selected at the top of the calculator. The area can be calculated in the previous steps or can also be inputted by the user. Then either the price per sq ft or the total cost should be provided to obtain the other value. Let’s look at a complete example:
  1. Input the size of the property’s (or property chunk’s) width and length in your desired units,
  2. Input the number of properties/chunks of the property with the size input above,
  3. [only if you didn’t follow the first two steps] Input the total area in your desired units,
  4. Input the total pricing of the property,
  5. Obtain the square footage pricing as dollars (or your local currency) per sq ft.

This is an example of one of the most straightforward scenarios, but it is very representative of the typical uses of this square footage calculator. We think that it is essential not only to know how to calculate square footage or how to measure square footage but also to know what you can do with those values once you get them.

When it comes to square footage pricing, its usefulness relies on the fact that it allows comparing properties (mostly houses) of different sizes and prices. It’s the equivalent of performance per dollar charts of computer parts, for example. In this manner, one could compare a 1500 sq ft with a 500 sq ft and know which one represents a better real state option, looking beyond just the price or the size of them. In fact, this can be used with any other area unit with or without converting from square meters to square feet or acres to square feet – every time we want to make a fair comparison.

How to use the square footage calculator

Before we get into the nitty-gritty of how the calculator works and what is the square footage formula, it’s useful to know how to use the calculator, and what each of the components mean. With the “One room/area” option selected, the square footage calculator is composed of the following fields:

  1. Shape – Select the room/area shape from rectangle, square, circle, triangle, hexagon or octagon
  2. Measurements – Various measurements of the room, which change depending on the shape selected
  3. Quantity – Enter the number of rooms/areas that have the same shape and measurements
  4. Area – Combined square footage of all the spaces as input above
  5. Unit price – Price (in the local currency) per square foot
  6. Total cost – Combined monetary value of the spaces described above

To use the calculator is as simple as setting the known values and letting the system calculate the rest. This means that you can use this calculator to compute the price per square foot of a property if you know the total price and total square footage.

If you select the option “Multiple rooms/areas” at the top of the calculate, you can enter the measurements for up to ten rooms or areas and get a grand total at the bottom of the calculator of the square footage. For complex room layouts, divide up the room into simple shapes, such as rectangles, squares, etc., and enter each one as a separate room/area. If you’ve entered a unit price, you’ll also get the total cost.

How many square feet is a 12×12 room?

The square footage of a room measuring 12 feet wide by 12 feet long is 144 square feet. To calculate this you simply multiply the width by the height. 12ft × 12ft = 144 sq ft.

How to calculate how many pieces of bullnose you will need?

If you have ten feet exposed edge that needs bullnose this is equal to 120″.  If you selected a 6″ bullnose or trim piece, you will need to divide 120″ by 6″, which will give you 20 pieces of bullnose needed.  Using 8″ decorative liner for the same 120″, you divide 120″ by 8″ which would be 15 pieces of liner needed.

Different Units of Measurement

Using square feet is the most common unit of measurement in American real estate. But it’s not your only option. For small projects, you might want to work in square inches. For big projects, like landscaping, square yards might make more sense. And in international real estate markets, square meters are the standard for home measurements. 

Whatever your unit of measurement, the formula is the same. Multiply the length times the width to calculate the area of square and rectangular surfaces. Just make sure you’re using the same unit of measurement for your length and width. If you’re looking for square feet, measure both distances in feet; if you’re looking for square meters, measure both distances in meters.

Why Tenants, Homeowners, and Landlords Need to Know Square Footage

There are several reasons why tenants, homeowners, and landlords should all know how to calculate square feet:

  • Knowing the square footage of a room can help you confirm if your furniture will fit.
  • Knowing the square footage of a specific surface can help you estimate renovation costs. If you’re replacing a kitchen countertop, for example, you need to calculate the square footage of the countertop so you can get accurate quotes for the cost of the job.
  • When you know how to calculate square feet, you can make sure you order the right amount of supplies and materials. If, for example, you plan to paint a wall that’s 12 feet long by 10 feet tall, you need to find the total square footage so you know how much paint to buy.
  • Perhaps most importantly, knowing the square footage of homes and apartments helps you compare prices to find the best value. Let’s say you’re deciding between two similar apartments: Apartment A is $1,500 per month and Apartment B is $1,800 per month. Which is the better deal? Well, it depends on the square footage. If Apartment A is 500 square feet and Apartment B is 1,000 square feet, you’re getting more space for your money with Apartment B. 

How to calculate the square footage of a house

When preparing to measure the square footage of a home, be it a house, condo, or townhouse, start with a few simple supplies:

  • Paper and pencil
  • Calculator
  • Measuring tape and/or laser measuring tool

If the property is a perfect rectangle, simply measure the length and width and multiply those two numbers together. For example, if your one-story house is 60 feet wide by 40 feet long, then your property is 2,400 square feet (60 x 40 = 2,400).

However, most properties have more complex floor plans. When this is the case, it’s helpful to follow these simple steps to measure square footage.

  1. Draw a rough sketch of your entire space, labeling all of the rooms you need to measure. Include hallways and vestibules as their own “room.”
  2. Measure the length and width, in feet, of each room. Then, multiply the length by the width to calculate that room’s square footage. For example: If a bedroom is 12 feet by 20 feet, it is 240 square feet (12 x 20 = 240). For each room, write the total square footage in the corresponding space on your sketch.
  3. Once each room is measured, add up all the measurements to determine your home’s total square footage.

Note If you live in a tract home, condo or townhome community, you may be able to get architectural drawings or master builder plans of your floor plan. These may already have your square footage calculated.

A First-Time Homeowners Guide on Everything You Should Know

Learn everything you need to be able to find and do in your new house with this — the Complete First-Time Homeowner’s Guide.

Read More