How to Measure Front Doors (2024)

• Jump to...
• How to Measure a Prehung Front Door
• How to Measure a Front Door with Sidelights
• How to Measure Double Doors
• How to Measure Double Doors with Sidelights
• Front Door Replacement Options

After you decide to replace your front entry door, it’s best to start by taking measurements so you can be prepared for conversations and to receive an accurate quote. Having these measurements will make sure you can get an accurate quote from a Pella representative or find a solution by shopping online. Learn about the parts of a front door before you measure.

The most common entry door size is approximately 36” wide by 80” tall. Follow along and learn how to properly measure your exterior door.

1. Start by measuring the width of the prehung door from the interior. Measure from one side to the other of the door panel, or the part that swings.
2. To find the door height, measure from the top of the door panel to the bottom on the edge of the door.
3. Measure the door thickness and door jamb width. For the door thickness, simply measure the edge of the door. To measure the door jamb depth, find the wooden frame that holds the door in place and measure the depth and height. This might require removing a section of the trim surrounding the door. Make sure to not include any trim in this measurement.
4. Finally, measure the door frame’s width and height. From inside your home, measure the inside edge of the trim from one side to the other.
5. To check to see if your door is square and level, measure the door from one corner to the opposite corner in an X pattern to see if the numbers match. If they do, this means your door is square. Use a level on the top and sides of the frame to make sure it’s plumb.
6. If you’re worried that your door may be warped or uneven, take three measurements for each — one at the top, middle and bottom or left, center and right of the door.

1. Measure the width of the exterior door. To do this, measure from one side of the door panel to the other. Then measure the width of the sidelights. Do this by measuring the distance between the inside of the jamb on both sides. Record the exterior door and sidelight values separately.
2. To find the door height, measure from the top of the door panel to the bottom on the edge of the door. Then measure the height of the sidelight, or the distance between the inside of the top jamb to the inside of the bottom jamb. Record the values separately.
3. Measure the exterior door thickness and jamb depth. To find the door thickness, measure the edge of the door. To find the door jamb depth, measure the depth of the wooden frame that holds the door in place. This might require removing a section of the trim surrounding the door. Do not include trim in this measurement. Record the values for each.
4. Finally, find the width and height of the door frame. To do this, measure the inside edge of the trim from one side to the other while in your home’s interior. Record the values.
5. To check to see if your door is square and level, measure the door from one corner to the opposite corner in an X pattern to see if the numbers match. If they do, this means your door is square. Use a level on the top and sides of the frame to make sure it’s plumb.
6. If you’re worried that your door may be warped or uneven, take three measurements for each — one at the top, middle and bottom or left, center and right of the door.

1. To measure the width of your exterior door, start on the outside of your home and measure from one side to the other across both door panels. Record the width.
2. Measure the height of your double door. Measure from the top of the door panel to the bottom on the edge of the door.
3. Find the door thickness and door jamb width. To measure the door thickness, simply measure the edge of the door. To measure the door jamb width, find the wooden frame that holds the door in place and measure the width and height. This might require removing a section of the trim surrounding the door. Make sure to not include trim in this measurement.
4. Finally, measure the door frame’s width and height. From inside your home, measure the inside edge of the trim from one side to the other.
5. To check to see if your door is square and level, measure the door from one corner to the opposite corner in an X pattern to see if the numbers match. If they do, this means your door is square. Use a level on the top and sides of the frame to make sure it’s plumb.
6. If you’re worried that your door may be warped or uneven, take three measurements for each — one at the top, middle and bottom or left, center and right of the door.

1. Measure the width of the exterior door. To do this, measure from one side of the door panel to the other. Record this measurement. Then record the width of both door panels together and record the value. Measure the width of the sidelights by measuring the distance between the inside of the jamb on both sides. Record the exterior door and sidelight values separately.
2. Measure the height of the front door, from the top of the door panel to the bottom on the edge. Then measure the height of the sidelight, or the distance between the inside of the top jamb to the inside of the bottom jamb. Record the values separately.
3. Measure the exterior door thickness and jamb depth. To find the door thickness, measure the edge of the door. To find the door jamb depth, measure the depth of the wooden frame that holds the door in place. This might require removing a section of the trim surrounding the door. Do not include trim in this measurement. Record the values for each.
4. Finally, find the width and height of the door frame. To do this, measure the inside edge of the trim from one side to the other while in your home’s interior. Record the values.
5. Check to see if your door is square and level. Measure the door from one corner to the opposite corner in an X pattern to see if the numbers match. If they do, this means your door is square. Use a level on the top and sides of the frame to make sure it’s plumb.
6. If you’re worried that your door may be warped or uneven, take three measurements for each — one at the top, middle and bottom or left, center and right of the door.

When it comes to replacing front entry doors, you have a wide variety of options. You could keep the current front door configuration by simply choosing a more up-to-date front door panel. Or you could completely change the door design. If your home currently has a double door configuration, you could choose to update your entryway with a single door panel with sidelights that fit your current opening.

After recording these measurements, you can feel confident taking the next step in the entry door replacement process. If you’re a DIY pro, buy a new fiberglass front door onlineand have it shipped straight to your home. Not ready to tackle a DIY project? Schedule an in-home consultation with a Pella replacement expert. They will handle everything from helping you find the right products and take final measurements to delivery and installation.