Door rough opening sizes: 32-inch, 36-inch (3/0), & more

Renovation can take quite a toll on your well-being. Apart from the hundred decisions, you’re required to make. There’s always room for something to go wrong. For example, your walls might end up painted in the wrong shade of white, or your marble floor may not fully complement your furniture. But these are mistakes that you can fix. You can always paint over a wall or change your floor tiling. However, incorrect size measurement is a mistake that lingers. 

Anderson exterior door

When measuring a rough opening, accuracy and precision should be the top priority because it’s pretty impossible to fit a door into an ill-matched rough. If you set out to fix our error, it will probably cost you more effort and money than you had initially planned. Therefore, you’ve to be particularly careful with the measurement. But to save you the trouble of figuring out the process on your own, we’ve devised a guide to help you. 

Please keep reading, and we assure you that an ill-fitted rough will no longer feel like an alien concept. We’ve also included charts to trace your door size and get the corresponding rough opening. 

Measuring rough opening

door ready to be installed

Remember, a door isn’t supposed to fit into the rough like a missing puzzle piece. Instead, there needs to be enough space for the structure to swing and all the other parts to rest comfortably.

The general rule of thumb is to add two inches to the width of the door to get the rough width. You need to add two and a half inches to the door’s height for the rough height. The additional space allows the wall to contract and expand during changing seasons. It also leaves enough room for the jamb on each side to rest.  

Rough opening for a 32-inch or 36-inch door (3/0) 

To measure the rough space for a 32-inch door, you must add a few inches. The rough opening for a 32-inch entrance is 34 wide. As for the height, you need to add two and a half inches to the door’s height. Typically, most entries are either 78 or 80 inches tall. So it would translate to an 80.5 or 82.5 inches tall rough opening. 

door that has been installed

For a 36-inch entrance, the same rule applies. Therefore, the rough opening is 38 inches wide and 2.5 above the door’s height.   

Rough opening for a 28 or 30-inch door

The general rule to measure the rough opening remains the same, regardless of the structure’s size. It is because it allows enough space for it to go through any seasonal changes and stay intact. 

For a 28-inch entrance, a rough opening of 30 inches in width would suffice. As for the height, the rough opening will be 80.5 inches high if the door measures 78 inches. Alternatively, the rough opening will be 82.5 inches tall for a door height of 80 inches. 

If you’ve got a 30-inch door, the rough opening will be 32 inches wide and 80.5 or 82.5 inches wide.  

Your entrance may have a different height. We’ve used a general assumption. In any case, your rough opening should be 2.5 inches taller than your door’s height. 

door that's ready to go in a rough opening

Door rough opening chart

Door Size (Width x Height)Rough Opening (Width x Height)
28” x 78”30” x 80.5”
30” x 78”32” x 80.5”
32” x 78”34” x 80.5”
34” x 78”36” x 80.5”
36” x 78”38” x 80.5”
28” x 80”30” x 82.5”
30” x 80”32” x 82.5”
32” x 80”34” x 82.5”
34” x 80”36” x 82.5”
36” x 80”38” x 82.5”

Double door rough opening chart

exterior double door

 

Door Size (Width x Height)Rough Opening (Width x Height)
28” x 78”30” x 80”
30” x 78”32” x 80”
32” x 78”34” x 80”
34” x 78”36” x 80”
36” x 78”38” x 80”
28” x 80”30” x 82”
30” x 80”32” x 82”
32” x 80”34” x 82”
34” x 80”36” x 82”
36” x 80”38” x 82”

Bifold door rough opening

The rules may be set in stone, but they vary from one design to another. Compared to a standard door, the rough opening for a bifold door is about the same height. But there is a slight variation in the width. This is because a bifold entrance doesn’t typically come with a door jamb kit, so the rough opening requires about half an inch less in width.  

To measure the rough opening for a bifold doorway, add two inches to the height and two to the width. For instance, a 32-inch entrance with 78 in height will have a 34 inches wide and 80 high rough opening.   

Pocket door rough opening

You might consider installing a pocket door if you’re tired of the conventional swinging design. It’s an excellent way to add a statement piece to your home. A pocket doorway also eliminates the need for extra space that a typical swinging design demands. 

However, the pocket entrance comes with its challenges. First, it requires additional space in the wall frame to slide into. It might not seem too demanding but measuring the rough opening gets trickier.  

The rough opening height is 85 inches, whereas the width is double plus one of the door width. For instance, the rough opening of a 32-inch pocket doorway will measure 65 inches wide and 85 high. 

Alternatively, a 24-inch pocket door will require a rough opening of 49 inches wide and 85 tall.  

Standard garage door sizes rough opening

Installing a garage or barn door is an easy task. You can take it up on the weekend, and the project will have come to a successful end before the next week starts. But that doesn’t mean that things can’t go wrong. If you mismeasure the rough opening, you’ll have to spend far more time and money to save the situation. 

Therefore, calculate the rough opening with utmost care. For a standard garage entrance, the rough opening is three inches wider and about one and a half inches higher—for example, a 35 inches wide and 81.5 inches taller than the standard 32-inch garage entrance.  

And if you’re planning to install a 43-inch door with a height of 84, then a rough opening of a width of 46 inches and a height of 85.5 will be ideal.    

Common door materials

glass interior door

Wood

When it comes to picking a timeless material, nothing beats wood. Its versatility makes it the top choice amongst homeowners. Regardless of the look, wood can complement all styles.

Depending on the finish, you can choose from the various wood types. For example, you can go for a mahogany or spiced walnut doorway if you prefer a darker finish. But if you’d instead install a lighter wood, honey maple, Salem, and light oak are your best options. If the door doesn’t match your aesthetic, you can add paint or varnish and take the entire design up a notch.

mahogany door

It is essentially the cheapest and easiest material to install at the entrance. However, wooden doorways require special care and maintenance. But if you’re prepared to bear the cost of periodic maintenance, there’s no option better than this. 

Steel

Steel doors are slowly but surely making their way into middle-class homes. Of course, a metal doorway may not be everyone’s style. But if you’re looking for an energy-efficient and durable material, steel is the best option. 

With a higher insulating value, you don’t have to keep the heater on all day when it’s sub-zero outside. Along with lower electric bills, steel designs also ensure excellent security. In case of an unfortunate home invasion, breaking down a steel entrance will take considerable time. 

steel door

Unlike wood, changing seasons won’t alter the physical dimensions of the material. So come rain or sunshine; steel is here to stay. You can even paint over steel to match your interior design. Despite its benefits, it’s much cheaper than a standard wood or fiberglass design. 

Aluminum

When you hear metal doorways, you probably think of using them to guard safes and high-security areas. We don’t blame you. Aluminum is a highly sturdy and durable material. It is distinguished for its strength and is often installed in areas with frequent storms and tornadoes.

However, it works just as fine if you wish to use it instead of steel or fiberglass ones. It offers the same strength but with less maintenance. It may be a little expensive, but you won’t have to worry about the material rusting. 

Fiberglass

Fiberglass has proven a great alternative to conventional materials. As a result, more people are moving away from installing traditional wooden entrances. The polyurethane core is better at resisting damage and providing insulation. 

Fiberglass will act as a savior if you live in a cold region, and energy costs account for most of your paycheque. You only have to leave the heater on for a few hours with such excellent insulation. Unlike metal, there’s no risk of corrosion or rust.  

However, the cost of installing a fiberglass entrance is something you need to consider before you jump into it. You may save up a few dollars on annual repair and maintenance, but it is nothing compared to the cost of the material and installation. Unfortunately, you can’t DIY a fiberglass installation. But if you can squeeze a few additional dollars, we highly recommend it. 

Stained glass

If you’ve visited a cathedral, you probably understand how each element adds to the ethereal aesthetic. Stained glass has been a massive part of Catholic history. But that’s not all. From ancient Romans to Egyptians, stained glass has been used to add character to churches, monasteries, and palaces. But even today, the material conveys more than just a stylistic choice. 

Stained glass panels are great insulators, so you’ll probably spend much less on energy. It also adds an element of privacy that other glass stores failed to provide. However, it will likely cost you more than a conventional door. 

But if you can make room in the budget, we suggest you take a leap of faith. 

How to frame a door rough opening

rough opening of a door that's being installed

Picking the right door might seem like a hassle, but it fades compared to installing a door. From measuring to nailing, here are all the steps you need to follow to frame an opening:

Step 1: Measure the door size

Grab a tape measure and note down the door size you plan to get. Of course, the measurements will vary depending on their function. For instance, the standard size for a garage entrance is about 96 inches wide and 84 feet tall. Alternatively, a standard interior entry will measure around 32 inches wide and 80 tall. However, we recommend not relying on a standard measure. 

Using the measuring tape, note down the width from one end to another and the height from top to bottom. Repeat the readings a few times to be sure.     

Step 2: Compute the door opening size

The rough opening size can be calculated using the door size you measured in the previous step. It is why accurate measurement is highly regarded. Once you have the doorway size, add two inches to the width and two and a half inches to the height to obtain the rough opening dimensions. 

Alternatively, you need to add two inches to the width and the height if you plan to install a bifold design. And if you’re thinking of a pocket style, fix the height to 85 inches and measure the rough opening width by doubling the door width and adding an inch.   

Step 3: Cut the frame

Once the precise measurements are down, it’s time to take out the big guns. First, cut the wood panels to make the studs and sole plate using a saw. The studs are equal to the height of the door, with an additional 1.5 inches. They provide structure and stability to the design. Lastly, cut the top header. This is the top of the entrance frame, measuring equal to the width of the entrance opening.   

Step 4: Assemble the various parts

Once you’ve all the individual pieces laid out, it’s time to assemble:

  1. Nail the top plate into place.
  2. Follow it with the sole plate. Once these panels are set, add on the studs one by one.
  3. It’s time to nail the header and the cripple stud.
  4. You can go ahead and cut off the sole plate in the door area. 

Step 5: Bring in the door.

Once the frame is securely set, you can move to the last step of installing a doorway. Bring over the structure to the frame and hinge it all into place. 

measuring a door

FAQs:

How much bigger should the rough opening be than the door?

For a standard interior door, the rough opening is about two inches wider and two and a half inches taller than the actual door size. 

However, the number may vary slightly with different styles. For instance, a bifold style rough opening is two inches wider and taller than the actual entrance. Alternatively, the rough opening of a pocket design is twice the width of the door plus one. In contrast, the height is fixed at 85 inches.  

What size door do I need for a 32-inch opening?

If you’re planning to install a conventional door, a 30-inch one would be ideal. However, only a 30-inch entrance would work since a rough opening is two inches wider than the doorway.  

What are standard door opening sizes?

The most common door widths in the US include 30, 32, and 36 inches. So going by that standard, you typically find a rough opening of 32, 34, and 38 inches.