Measuring for a Garage Door Rough Opening

by DoItYourself Staff

You need to know the measurements of the garage door rough opening to replace a garage door. These measurements are required for the installation of a new door, vertical track, spring system and an automatic garage door opener.

Garage Door Rough Opening

Measure the width and height of the garage door rough opening.

Side Room

Measure the left and right side room. The side room is the space on either side of the garage door rough opening. At least 3 ¾ inches is required for the vertical track installation.

Headroom

The headroom is the distance between the top of the door opening to the ceiling. You need 10 inches for a standard extension spring.

Back Room

The back room is the length of the garage ceiling. Start measuring at the garage door opening to the back wall of the garage. You need 18 inches plus the height of the door for the back room.

Common Sizes for a Garage Door Rough Opening