What Is a Door Jamb's Size?

Door jambs are and element of the door frame and play an essential part in the running of your door. They’re used to attach the hinges on your door and hold the strike plate for the door’s latch. Without door jambs, you wouldn’t have a fully-functioning door.

For interior doors, a door jamb’s size is 4 ⅝-inches in-depth - this is the standard size for a door jamb. With this depth, you’ll get ⅛-inch extra to accommodate for walls that may be a little thicker than the standard.

Other Door Jamb Sizes

Of course, there isn’t a one-size-fits-all policy when it comes to doors. You may find that the measurements above are too large, or too small, for your opening. Other typical sizes for door jambs are:

• 4 9/16-inches if you have a 2x4 frame and a ½-inch drywall

• 5 ½-inches if you have a 2x4 frame and a thick drywall

• 6 9/16-inches if you have a 2x6 frame or a block wall.

Take a look at our internal door sizing guide to find out more about the common door sizes. 

How do you measure a door jamb?

To measure your opening for a door jamb, you need to measure the width wall to wall. Once you have this figure, add ⅛-inches to ensure that the door jamb will fit, even if the drywall is thicker than expected.