8X7 Garage Door Rough Opening (Must Know Things)

By - Hs Saini

Updated -

If the home you are building will have a garage space, the garage door should be an essential part of your garage plan.

There are different garage door sizes, from standard to custom door sizes. But before purchasing a garage door, you must measure the size of your door’s rough opening. 

The width and height of your garage door can vary, depending on varying factors, including the number of vehicles you own. So, what is the rough opening of an 8X7 garage door? 

The garage door rough opening of a 7-foot by 8-foot door is 8 feet, 3 inches by 7 feet, 1.5 inches tall. Therefore, you can calculate any garage rough opening by adding 3 inches to your garage door height and 1 to 1½ inches to your door width.   

What Is the Rough Opening for an 8’ by 7’ Garage Door?      

8X7 Garage Door Rough Opening 

The rough opening size for an 8-foot width by the 7-foot tall garage door is about 8 foot 3 inches wide and 7 feet 1.5 inches tall.

You can calculate the rough opening similarly to other garage door sizes. However, you must add extra inches to the gate size for the garage rough opening to accommodate the garage door frame. 

To measure the door rough opening of your garage, you should add at least 3 inches to the door width and 1 to 1.5 inches to the garage door height.

The rough opening of the garage door is the garage opening size before you install the finished wood frame.

After adding your garage door frame, the finished space will be the same size as the garage door you want to install in your garage. 

If you purchase a garage door the same size as your rough opening, the door might not fit into the finished opening.

This situation is why you should add extra inches to the garage door you intend to buy when measuring your garage door rough opening. 

To achieve the correct measurement for your garage door opening, frame your door rough opening 3′ wider and 1.5′ higher than the garage door you intend to use. 

#1. How to Frame Your Garage Door Opening?

After framing the rough opening, you would have your finished space. The opening will be 8′ wide by 7′ tall, the same size as the garage door you purchased.

If you are DIYing your garage, you can frame your garage door opener yourself. The following steps are guides on framing your door:

#1. Step 1- Purchase the Necessary Tools

Before framing the garage door, you will need some work tools and equipment.

This equipment includes a tape measure, a circular saw, a pencil, and a few two-by-six-inch lumber or PVC door jambs.

You must select the type of lumber before determining the garage door opening. 

#2. Step 2- Estimate the Rough Opening of the Garage Door

Ensure the rough garage opening is larger than the size of the garage door you purchased before installing the frame.

Measure the area between the garage header and floor and ensure the length is about 1.5 inches greater than the length of your garage door.

Finally, measure the space between the door’s rough opening width on the left and right sides. The width should be about 3 inches more than the garage door.

#3. Step 3- Fix the Door Jambs

The door head jambs are the lumber at both sides of the door opening and the header. You must install the door head jambs before installing the side jambs.

Add nine inches to the garage door length, and compare it to the length of the header so that it fits into the horizontal space of the garage. 

Cut your lumber or your PVC jamb and use framing nails to attach it to the garage header.

Ensure the header is thick enough to cover the space between the garage door height and the rough opening.

#4. Step 4- Calculate the Height Between Your Floor and Ceiling

You’ll need two framing pieces for the wall beside the garage opening. This framing will hold the door track to the garage wall.

If you are a door installer, you would know this frame as a “goal post.” After measuring the height between your opening floor and ceiling, cut out the lumber for the frame you measured. 

Join the two pieces of lumber framing to the interior part of your garage with framing nails. Allow the framing to run up against the door head jamb you fixed.

#5. Step 5- Attach the Door Side Jambs

With the height of your new opening, cut out two pieces of PVC door jambs. The door side jambs should be against the jamb header you installed.

Use double-side jambs to hold the weight so you can install the trimmers on either side.

After the side jambs installation, your garage door size will have the same dimension as your new garage door.

#6. Step 6- Install the Center Bracket Framing

Cut a piece of PVC door jambs or lumber according to the height between the header you attached to the ceiling.

Center the door jamb on the header. With this piece of framing, the door installer will be able to install the center bracket of your door spring system.

#2. Difference Between Rough Opening and Finished Opening

ParametersRough OpeningFinished Opening
SizeIt should have a larger size than the garage doorIt should have the same size as the garage door
WidthYou have to add 3 inches to the rough opening widthNo additional width required
HeightYou have to add 1-1½ to the rough opening heightNo additional height required
DefinitionThe size of your garage door opening before you install the door frameThe size of the negative area remaining after installing your garage door frame

Clopay 8×7 Garage Door Rough Opening 

As per the Clopay door installation guide, the garage door rough opening for an 8′ x 7′ Clopay garage door should be 8’2″ wide x 7’1.5″ tall.

Depending on the garage type, the finished opening of your garage should have the exact measurement of the door you bought.

The garage door should fit the finished opening of the garage door from the inside.

Use a stop molding or an exterior perimeter seal to protect the rough opening from moisture and wind.

You may need a headroom of about 10 inches for the garage door to function. The headroom size often depends on the spring system you will install in your garage door.

What Is the Standard Opening for a Garage Door?                         

The standard opening for a garage is about 8 feet – 9 feet wide by 7 feet – 8 feet high. This measurement is mainly for single garage doors.

If the garage door opener does not have proper spacing, installing the garage door might be an issue.

For double garage doors, the standard space is about 16 feet wide by 7 to 8 feet tall.

Custom garage door sizes can be ten or more feet high. This garage can accommodate trucks and RVs.

In this case, standard size measurement will be impossible. The thickness of your typical garage doors determines the amount of insulation your garage will have.

However, purchasing an insulating garage door might not be cost-effective, especially if it is not necessary.   

What Should the Rough Opening Be for an 8×7 Garage Door With a 1X Finish?            

The rough opening for an 8′ x 7′ garage door with a 1x is 8’3″ wide by 7’1″ high.

Finishing the rough opening of the 1x finish garage door involves installing the PVC door jambs for the garage door and installing tracks and springs to anchor the frames.

It is also necessary to install the side and centerboards at the sides of the garage frame and above the door header.

The center boards should cover the door header to the ceiling. You can also use a 2 x 4 lumber to give the header an aesthetic feel.


The measurement of your garage door rough opening is essential to install your new garage door without any hassles.

Before installing your garage door, ensure you have the right tools and rough garage opening measurement. Consult your door installer for more information on preparing your door frame.

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