How to Remove and Replace an Entry Door

Measuring door casing on old entry door.

Measuring door casing on old entry door.

How to Measure for an Entry Door

To determine the size for a new entry door, measure the existing door unit:

  1. Measure the width and height of the existing door.
  2. Measure the width of the door jamb between the interior and exterior door casings to determine the thickness of the wall. Door jambs are the sides of the door frame that are perpendicular to the door and cover the wall studs. On a standard 3½” stud wall, the door jamb usually measures 4 5/8” wide to allow for 1/2″ drywall on the inside and 1/2″ plywood sheathing on the outside.
  3. Measure the outside dimensions of the door casings around the door frame. Door casings are the top and side pieces of the door frame on the inside and outside that attach to the wall studs and door jambs to hold the door in place. Most exterior doors have 2” wide by 1¼” thick brick mold for the exterior casing around the door, and 2¼” to 3¼” wide by 11/16” thick molded trim casing on the interior.
  4. Take the measurements to your building supply or home center and match the size of the door, thickness of the jamb, and exterior dimensions of the casing to the existing door on your house. The interior dimensions of the casing are not as crucial, since the casing overlaps onto the wall.


Please Leave a Comment

8 Comments on “How to Remove and Replace an Entry Door”

You can follow comments to this article by subscribing to the RSS news feed with your favorite feed reader.

  • Official Comment:

    Thomas Boni Says:
    January 25th, 2019 at 4:36 pm

    Hi, Lillian,

    We are so happy to hear that you enjoy “Today’s Homeowner!”
    If you haven’t already, please…

    *Follow us on Facebook:
    *Like us on Twitter:
    *And check out Instagram and Pinterest pages! ( and

    And we always appreciate when our fans tell their friends about the practical home improvement advice they receive from “Today’s Homeowner.”

    Thanks so much for watching — take care!

  • Lillian Schaeffer Says:
    January 25th, 2019 at 4:12 pm

    Thanks for letting me know that wood beginning to rot is a sign you need to replace the door. My door has begun to have this issue, and I want our home to remain secure. Maybe it would be best to replace the door as soon as possible.

  • RobertoDixon Says:
    April 19th, 2016 at 12:54 am

    Great post!!!

  • Zequek Estrada Says:
    March 31st, 2016 at 7:20 pm

    I think I may need look more into refinishing and refurnishing. Though my door does have some issues, like wood deterioration, but I don’t think it’s that big of a deal. I think I’m just in the mood for change.

  • jeffrey g blais Says:
    November 29th, 2015 at 8:57 am

    Need to replace door sweep. door pins are spring loaded. found vidos to remove pin. Whats next, its a knuckle buster after the pins come out. found no futher info. Jeff.

  • Steve Says:
    September 7th, 2015 at 1:55 pm

    I want to install a 36 inch prehung to a 35 inch opening. Can I remove the double stud framing or do you have a better idea?

  • Anne Says:
    April 10th, 2014 at 4:57 pm

    I’ve done a lot of research and I would recommend a fiberglass door that is made to look like wood. This way it would continue with the look of your home but provide better insulation for hot or cool weather.

  • Ramona Flanagan Says:
    December 10th, 2013 at 2:56 pm

    We have a older home 1937 with a wooden entry round top door. Need to replace it, would like to do so with a square one, what are our options?

We want to hear from you! In addition to posting comments on articles and videos, you can also send your comments and questions to us on our contact page or at (800) 946-4420. While we can't answer them all, we may use your question on our Today's Homeowner radio or TV show, or online at

 characters available

How to Remove and Replace an Entry Door