Knowing how to measure a room, and accurately at that, helps with many home improvement projects, especially flooring and painting. Moreover, when you know the right size, it’s easier to decide on how much carpet to purchase, or figure out how big your new sofa can be without making your living room cramped

Of course, sometimes, you need different measurements for different tasks. For example, you will need to calculate just the area to put in a new flooring. A paint or wallpaper job, on the other hand, will even factor in the area of the walls, ceiling, doors, or windows.

So, whether you’re renovating your house in a big way or it’s as simple as determining the size for an addition to your home, knowing how to measure a room and calculate its square footage is a necessary part of creating your ideal space. 

Planning a home remodeling? Use our free renovation estimator to have a fair idea of the total expenditure of your project. 

This article will delve into the various techniques on how to measure a room — ranging from precise measurements to rough estimates, with each having its own purpose. So, let’s begin. 

1. Measuring tape

Measuring tape
Photo by Freepik

The most common method of calculating the square feet of a room is with a measuring tape. For any square or rectangular room, you can use a 25-foot tape and a fastener — since most rooms are under 25 feet long or wide. 

Though these are not ideal for single operators, you can latch the front end of the tape to a stable ledge on one side of the room and slowly pull it back until it has reached the other side. 

However, an inherent flaw in tape measures to calculate the length and width of the room is their tendency to bow and bend when stretched across long distances. This can result in the occasional fluctuations of correct measurements.

2. Laser tape measurement

Laser tape
Photo by Freepik

If the above method proves frustrating (and it does to some), consider measuring the area of the room with laser tape. Though laser tapes are pricier than the manual types (about $40 to $60), they can cut the time of labor into fractions and produce very accurate measurements, within 1/16th of an inch. 

Just place the laser tape on one side of the room and face the laser on the opposite wall. Once the laser point is visible, a single press of the button will measure the distance (including the length of the laser tape itself).

3. Foot measurement

When neither of the above-mentioned methods is at your disposal, your feet can double up as a valuable measuring tool. After closely measuring the length of your foot, you can start on one side of the room and carefully put one foot in front of the other, until you reach the other side. 

In the process, count the number of footsteps out loud. Multiply the number of footsteps by the length of your foot in inches, then divide by 12 to get the measurement in feet.

4. Height measurement

If you’re stuck without a tape measure, another way to measure a room is as simple as comparing it with your height. Simply lie down on the floor and let someone mark where your head or toe is so that when you get up you won’t lose your marker. 

However, if you don’t have someone with you, use a pen or paperclip to mark where you should next lie down.

The downside to measuring a room with your height is that the room needn’t be evenly distributed. So when you reach the end of the room, you’ll have to do some guesstimating. Though this type of measurement isn’t the most precise, it’s certainly faster than using your feet across a large room.

5. Arm measurement

As the name suggests, you’ll have to keep your arms outstretched and use the distance across your chest between the tips of your fingers to measure a room. Basically, you are using your body’s wingspan to measure across an empty wall. 

Keep count of how many times your arms’ width fits along with the room. Hold your finger in place and move to the next starting point. Simple! Moreover, if the wall doesn’t perfectly fit in your arm measurement, you can use half the width of your wingspan and calculate its size accordingly.

FYI: The measurement of your arms outstretched is usually equivalent to your height.

6. Binder measurement

Yes, you read right. Even a handy ring binder can help you figure out the measurements of a room! Carefully count how many binder lengths it takes to get from one side of the room to the other. Generally, a one-inch, three-ring binder measures 11.5” in length. Keeping this fact in mind, you should be able to estimate the room’s measurement.

Once you find the technique that fits your needs, simply measure both the length and width of your room. Just remember to create a line perpendicular to the walls on either end. Since most rooms are either square or rectangular, making a line parallel to the adjacent wall works just as well.

How to measure a room for square footage?

Room measurement
Photo by Pxhere CC0

To know how to measure square feet, you need to measure the width and length of an area and simply multiply them in the case of a square or a rectangle.  

Remember to measure this from the inside of the room. 

Length (ft) x Width (ft) = Square footage

This method may vary depending upon the shape of the area. For example, for an L-shaped area, you can split the area into two separate sections making squares or rectangles of both sections. 

The next step would be to measure the area and then add them together for the total square footage. 

Keep in mind that your measurements should be in one unit, preferably square feet. If your measurements are in different units, you will need to convert them into a single unit.  

You can refer to the conversion table below: 


Unit conversion calculation into square feet

InchesDivide the value by 12
YardsMultiply the value by 3
MetersMultiply the value by 3.281
Centimeters Multiply the value by 0.03281
MillimetersMultiply the value by 0.00328084

How to measure a room that is not square or rectangular?

If your room is not a square or rectangle, then the simple length x width area will not work. Instead, you can divide the space into different shapes (circles, triangles, smaller squares, or rectangles). You can sketch it out to help you visualize the space and divide it up, or use a painter’s tape to divide the room into different areas/shapes. 

From there, you can take the measurements of each shape. And then, simply add the areas.

If you have trouble drawing up plans or figuring out how to accurately divide a differently shaped room, check out this write-up on how to work with an architect. The added experience can be immeasurably valuable, especially for larger projects.

Calculations on how to measure a room

After all the measurements have been taken, it’s time to do some math. For rectangular spaces, simply multiply the length and width of the room to calculate the total areas or square footage. For square spaces, do the same, although you’ll have the same measurement for length and width. Other shapes require different formulas:

  • Triangles: Area = 1/2 base x height
  • Circles: Area = π (pi) x the radius squared (radius x radius)
  • Semicircles: Area = π (pi) x the radius squared (radius x radius), then divide by half

Once you’ve calculated the area of each shape, add them together to get the total square footage of your room, and you’re done.

How do you calculate the square footage of a house?

If you want to know how to measure the square feet of your entire house, you can use the same calculations, but on a bigger scale. The longest side of your house will be the length while the shorter side will be the width.

For example, if your house is 60 feet by 40 feet long, then the total square footage of your property will be 2,400 square feet (LxW). 

When calculating square feet, make sure that the calculations include all spaces within exterior walls, even if it includes interior walls or dead space. 

Remember that stairways, closets, and cabinets are included in the square footage of a house. So also is a finished attic that has a minimum clearance of seven square feet. Interestingly, covered porches are also included, provided they are heated using the same thermal system as the rest of the house.

A garage, on the other hand, is not considered part of a home’s square footage. Keep in mind that only livable spaces are included in the square footage calculation.

Remember when you’ve completed these projects, always record the data in an organized manner. Many first-time renovators take on more projects after they have completed their first, and having this information on how to measure a room on hand can save a headache or two in the long run.

Do you need more input on your project? Try our full home improvement guide and get started!

6 Best Ways on How to Measure a Room was last modified: October 11th, 2022 by Shane Reiner-Roth
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This task just got a serious amount easier and a serious amount more accurate as of today and Apple’s Augmented Reality. look for “FloorArea AR” in the App Store