Garage Door Rough Opening – 8′ – 10′ – 9×8 – 16×8 – opening Size

Saad Iqbal | 🗓️Modified: November 28, 2023 | ⏳Time to read:4 min

For a garage door replacement project, you need to know how to measure for garage door. But make sure you know the terms like rough opening, rough framing, and finished opening

Measuring rough opening of a garage door include measuring the width and height of rough opening along with headroom, side room, as well as backroom.

Table of Contents

What is RO?   

In general framing concepts, RO or rough framing is a size of opening that accounts for adjusting door or window in the position.

So, the size of clear opening is larger than the standard dimension of doors and windows. The main reason behind this difference is to consider framing and space for shimming.

Are you looking to get a new garage door or may be replace an existing one? If yes, we have made a new guide for you about how to measure for your garage door?

Rough opening or rough framing is the size of the opening before installing the finished framing. It is to leave room for the frame and has to be larger than the size of your garage door.

For a typical garage door, the rough opening height is 1.5″ more than the width of the garage door while the width is generally 3″ wider.

Rough Opening for garage doors
Rough Opening for garage doors

Finished opening

After you’ve finished installation of framing, the remaining space left is the finished opening. The finished opening can be same or slightly smaller than the size of the garage door.  So, if you’re going to buy a garage door of 16×7 feet; the finished opening should also be 16×7 feet.

A garage door of different sizes is used in different countries depending upon the width of vehicle and number of vehicles to park. The size of garage door is larger than the simple doors.

Rough width of opening

Rough opening for garage door should be 3” wider than the width measured between left and right edges. For example, if we want to install a 10 feet wide door then we will have to provide 10 feet and 3-inch-wide.

Rough height of opening

For height of garage door, the RO should be 1.5” more than the distance measured from garage floor to top rough header. For example, if the height of door is 8 feet, then RO for height of garage door will be 8 feet and 1.5 inch. It’s the height you must manage before you can add framing elements.

The header at the top goes along wider than the door by as much as 9 inches.

Also Read: Pest-Proof Your Home: Proactive Measures for Long-Term Relief

Common sizes of garage doors

The garage door size varies according to a place where we live.

  • Common size of Garage Door – single car parking – 8’ wide and 7’ tall.
  • Double car parking garage door – 16′ wide and 7′ tall.

For installation of all sizes of garage door the adjustment for framing and shimming is done while providing opening to avoid size issue of door.

Common widths sizes

The common sizes which are mostly used for garages are: 8’, 9’ ,10’ ,12’, 16’ ,18’ wide.

Also Read: Types of doors

Different size garage doors

For all size of garage door, the RO will be calculated by adding 3” on width of door and 1.5” will be added to height of door.

Door Size (width x height)RO width (adding 3”)RO height (adding 1.5”)
5×65’-3”6”-1 ½”
16×716’-3”7”-1 ½”
16×816’-3”8”-1 ½”
18×818’-3”8”-1 ½”
10×910’-3”9”-1 ½”
10×1010’-3”10”-1 ½”
8×78’-3”7”-1 ½”
9×7 9’-3”7”-1 ½”

For rough opening 3” is added to width of door and 1.5” to height of door. The RO of garage door is necessary for accurate installation of door in opening.

Saad Iqbal is a professional civil engineering and freelance write. He's passionate about structures, construction management, and home improvement topics. He's been working as a Senior Engineer in a consultant firm for over 8 years. Besides he loves writing informative and in-depth content focused on construction and home-related topics. You can catch him at his linkedin page or reach out via our contact us page.

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