Door Size Buying Guide

Determining the size of your door is as simple as taking a few measurements and doing some basic math. You just need to find the height and width of the door using a measuring tool. Once you have measured these accurately, you can start on whatever your home project is, like replacing the door, installing a new style door, or decorating the one you currently have.

Step One: Take Measurements

Measure the width of the door. Run a tape measure along your door from the left corner to right corner, and record this number. It is important that you only measure the door. Do not include any other elements, such as weather-stripping.

  • Particularly with older doors, it is important to measure in more than one location, just in case the door is not perfectly rectangular. If the amounts vary, use the largest figure.
  • Door widths of 30 inches (76 cm), 32 inches (81 cm) and 36 inches (91 cm) are considered "standard." 


Determine the height of the door. Run your tape measure along your door from the top corner to the bottom corner, and write this number down. You may need to use a chair and/or ask a friend to help you. Once again, measure only the door itself and no other elements, such as a door sweep.

  • Once again, it is wise to measure in more than one spot on the door, just in case it's not a perfect rectangle. This is especially true for older doors. If the amounts vary, use the largest figure.
  • The most common height for doors is 80 inches (200 cm)


Figure out the thickness of the door. Hold a tape measure to the edge of the door and record its thickness. Measure this edge on the door frame (known as the jamb), as well. These numbers should be close to the same, but it can be helpful to know both of them. The most common thickness is 1.75 inches (4.4 cm). 


Measure the height and width of the framed door space. Just to be safe, measure the area where your door will go, too. Record the height and width of the door frame space. This will help ensure that you select the exact right replacement door.

    • Measure the width of the door in 3 locations. Use the smallest figure as your measurement.
    • Measure the height of the door right in the middle. Measure from the floor to the underside of the trim at the top of the door.
    • If you must, it is always better to round down than round up. This helps to ensure that your door will fit.




    Take a picture of your door and print it out. When you go in to select a replacement door, you should bring along a diagram with all relevant characteristics and measurements. One easy way to do this is to photograph your door and print out the image. You can also simply draw a diagram with paper and pen.

    Label the swing direction of your door. Open your door. Position your body so that your back is against the hinges. If the door is on your right, it is a right-handed door. If the door is on your left, it is left-handed. Your door will also either be in-swing or out-swing. Determine both of these characteristics and record them on the diagram you made.

    • An in-swing door opens into your house (or into a room), and an out-swing door opens outward.

    Record all of the measurements on your diagram. Write the height, width, and thickness of your door down on your diagram. Write down the height, width, and thickness of the door frame, as well.

    Bring this diagram to our store when you shop for doors. This diagram should make the process of replacing your door a lot simpler. Bring it with you any time you look at doors, and use it to guide your purchase door.