How to Measure a Room for Your Remodeling Project?

How to Measure a Rectangular Room

The principles of measuring a square or rectangular room are simple, requiring just two steps.

Step One: Take Measurements

Choose two perpendicular walls (walls that intersect to form a corner) and measure the length of each using a tape measure.

Step Two: Calculate Square Feet

Use your calculator to multiply the two measurements. For example, a square or rectangular room that has one wall that measures and 8 feet long and a perpendicular wall that is 10 feet long will result in the follow equation.

8 ft × 10 ft = 80 sq ft

Thus, this room is 80 square feet.

There are also online square footage measurement tools that can multiply these measurements.

Got it? That may seem basic, but what if the room isn’t square or rectangular?

How to take multiple measurements

  1. After you take the first measurement, move your device to place the dot over another location on or near the object.
  2. Tap the Add button 
 to start the second measurement, then move your device to place the dot somewhere along the existing measurement.*
  3. Tap the Add button 
 again and the second measurement appears.
  4. Repeat these steps to take as many measurements as you’d like.

Tap the Undo button * Additional measurements must start or end somewh to remove the most recent measurement, or tap Clear to start over.

* Additional measurements must start or end somewhere along an existing measurement. Otherwise, all previous measurements are replaced by the newest one.


How to Measure Walls for Paint or Wallpaper

To accurately measure a room for wall coverings we will use the length of the wall, and the height to the ceiling. The formula will be similar to before.

Step One: Take Measurements

Start by measuring the length of the wall and the height of the ceiling using a tape measure. If you have multiple walls, then do this for each wall surface.

Step Two: Calculate the Area of Each Wall

Next, use a calculator to multiply the length and height, just like before. If, for example, the wall measures 12 feet long and 8 feet high, use the calculator to figure 12 feet × 8 feet and see that the wall is 96 square feet.

Step Three: Add the Wall Areas Together

Repeat this process for each segment of wall in a room to accurately measure a room for any type of wall-coverings. Add the areas of each wall together to get the total square footage of all the walls.

Step Four: Subtract Doors and Window Openings

When measuring for some materials such as paint it might be important to subtract surfaces that will not be covered like doors or windows. Note that when measuring for some material accounting for doors and windows may not be necessary and this step can be skipped.

As you make your way around your room, measuring the square footage of each segment, make sure that you note any doors and windows. Measure the length and width of each one, then multiply to find the area. Finally, subtract each door and window area from the total.

One quick tip: our wallpaper and paint calculators can help estimate wall covering materials after you’ve measured your walls and simplify this whole process, so it might be worth checking them out.

Use the Measure app with iPad Pro 12.9-inch (4th generation), iPad Pro 11-inch (2nd generation), iPhone 12 Pro, and iPhone 12 Pro Max

iPad Pro 12.9-inch (4th generation), iPad Pro 11-inch (2nd generation), iPhone 12 Pro, and iPhone 12 Pro Max use the LiDAR Scanner to help you measure objects more quickly and accurately with the Measure app.

Not sure if your device has a LiDAR Scanner? Find out which iPad model you have or which iPhone model you have.

Measure a person’s height

When the Measure app detects a person in the viewfinder, it automatically measures their height from the ground to the top of their head, hat, or hair. You can tap the shutter button  to take a photo of the person with their height measurement. Then you can use Markup on the photo, save it, and share it. Here are some tips for getting a good height measurement: Make sure that you’re in a place with good lighting. Avoid dark backgrounds and reflective surfaces. Check that the person you’re measuring has nothing covering their face or head, like a face mask, sunglasses, or a hat. Try to step back from the person you’re measuring. You might be standing too close.

Use vertical and edge guides

On iPad Pro 12.9-inch (4th generation), iPad Pro 11-inch (2nd generation), iPhone 12 Pro, and iPhone 12 Pro Max, guide lines help you measure the height and straight edges of furniture, countertops, and other objects easily and precisely. Guide lines appear automatically along edges and when making a vertical measurement.   Snap your starting and ending points to the yellow guide line, then tap a measurement to see the expanded information that iPad Pro provides. You can view the measurement’s elevation, distance away, angle, and more.

See more granular measurements with Ruler View

The Measure app on iPad Pro 12.9-inch (4th generation), iPad Pro 11-inch (2nd generation), iPhone 12 Pro, and iPhone 12 Pro Max adds a ruler overlay to line measurements, showing you the object’s dimension in granular increments. Move your iPad Pro close to a line measurement to see the ruler view appear, then tap the shutter button to take a photo so you can use the increments for planning projects.

See your measurement history

Tap the list button  to view all the measurements that you’ve taken during the current session, including screenshots that you took. This helps you keep track of dimensions as you measure a space or series of objects. You can copy the dimensions into Notes, Mail, or any app you want to save your list in, or clear them to start over.


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