Interior Door Rough Opening Size Calculator

For common interior doors, the rough opening width should be approximately 2 inches wider than the door’s actual width. The rough opening height should be around 82.5 inches, providing ample clearance. As an example, for a standard 30-inch interior door, aim for a rough opening of 32 inches in width and 82.5 inches in height. Specific requirements may vary, so consult local building codes and door manufacturer guidelines.

Interior Door Width	Rough Opening Width	Rough Opening Height
24 inches	26 inches	82.5 inches
28 inches	30 inches	82.5 inches
30 inches	32 inches	82.5 inches
32 inches	34 inches	82.5 inches
36 inches	38 inches	82.5 inches

FAQs

How big should a rough opening be for an interior door?

• A rough opening for an interior door is typically about 2 inches wider and 2.5 inches taller than the actual door size. This provides space for the door frame and allows for adjustments during installation.

What is the rough opening for a 36-inch interior door?

• A rough opening for a 36-inch interior door would be approximately 38 inches in width and 82.5 inches in height.

What size door fits a 32-inch rough opening?

• A door that fits a 32-inch rough opening would typically be a 30-inch wide door.

What is the rough opening for a Prehung interior door?

• The rough opening for a Prehung interior door is usually about 2 inches wider and 2.5 inches taller than the nominal door size.

How much bigger should my rough opening be?

• Your rough opening should be about 2 inches wider and 2.5 inches taller than the nominal size of the door you intend to install.

How much bigger should door opening be than frame?

• The door opening should be slightly larger than the door frame to allow for ease of installation. Typically, a 1/8-inch gap on all sides between the door frame and the opening is sufficient.

What is the rough opening for a 36-inch Prehung?

• The rough opening for a 36-inch Prehung door might be around 38 inches in width and 82.5 inches in height.

What is the rough opening for a 36×80 Prehung door?

• The rough opening for a 36×80 Prehung door would likely be approximately 38 inches in width and 82.5 inches in height.

Is a 36-inch door really 36 inches?

• No, a 36-inch door is not exactly 36 inches wide; it is typically around 35.75 inches wide.

Is a 32-inch door actually 32 inches wide?

• No, a 32-inch door is not exactly 32 inches wide; it is usually slightly narrower, around 31.75 inches wide.

What is the rough opening for a 32×80 door?

• The rough opening for a 32×80 door might be around 34 inches in width and 82.5 inches in height.

How wide is a 32-inch Prehung door?

• A 32-inch Prehung door is typically about 31.75 inches wide.

What is the standard internal door opening?

• The standard internal door opening typically ranges from 28 inches to 36 inches in width.

What if a Prehung door is too wide for the opening?

• If a Prehung door is too wide for the opening, you may need to trim the door frame or the door itself to fit properly.

What is the difference between an interior door and a Prehung door?

• An interior door refers to the door panel itself, while a Prehung door includes the door panel, the frame, hinges, and often the knob or handle, all pre-assembled and ready for installation.

How accurate should rough framing be?

• Rough framing should be reasonably accurate, but small variations are acceptable since finishing materials can often cover minor imperfections.

Is a 30-inch door really 30 inches?

• No, a 30-inch door is not exactly 30 inches wide; it is typically around 29.75 inches wide.

What if my rough opening is too small?

• If your rough opening is too small, you may need to enlarge it by reframing the opening to accommodate the desired door size.

How big does a door opening need to be?

• A door opening typically needs to be about 2 inches wider and 2.5 inches taller than the nominal size of the door being installed.

How much gap do you leave between door and frame?

• A common gap between the door and the frame is around 1/8 inch on all sides for proper clearance.

What is the gap between door and frame called?

• The gap between the door and the frame is often referred to as the “reveal” or “clearance.”

How do you calculate the rough opening of a door?

• To calculate the rough opening for a door, add about 2 inches to the width and 2.5 inches to the height of the actual door size.

What is the actual size of a 36-inch Prehung door?

• The actual size of a 36-inch Prehung door is typically around 35.75 inches in width.

Why are doors 36 inches wide?

• Doors are often made slightly narrower than their nominal size to allow for proper clearance and ease of installation.

What is the actual size of a 36×80 door?

• The actual size of a 36×80 door is typically around 35.75 inches in width and 79.5 inches in height.

Are most doors 32 or 36 inches?

• Both 32-inch and 36-inch doors are common sizes for interior doors, but 36-inch doors are often used for wider openings and for accessibility.

Can a door be 30 inches wide?

• Yes, doors can be 30 inches wide, and this is a common size for many interior doors.

What is the rough opening for framing doors?

• The rough opening for framing doors should be about 2 inches wider and 2.5 inches taller than the actual door size.

What is the rough opening for a closet door?

• The rough opening for a closet door is typically similar to the rough opening for other interior doors, about 2 inches wider and 2.5 inches taller than the door size.

How do you measure an interior door?

• To measure an interior door, measure the width and height of the door slab, excluding the frame.

How wide is a prehung door frame?

• The width of a Prehung door frame can vary, but it’s often around 4.5 to 6 inches.

How wide is a 32-inch door slab?

• A 32-inch door slab is typically around 31.75 inches wide.

What is the most common door size?

• The most common door sizes for interior doors are 30 inches, 32 inches, and 36 inches in width.

Do internal doors have to be a certain size?

• Internal doors do not have to be a specific size, but they should be chosen based on the function and size of the room or opening.

How much smaller should a door be from the opening?

• A door should be slightly smaller than the rough opening, leaving a small gap of around 1/8 inch on all sides for clearance.

How much can I cut off the bottom of a Prehung door?

• You can typically trim up to 1 inch from the bottom of a Prehung door without affecting its structural integrity.

Can you get a door wider than 36 inches?

• Yes, you can find doors wider than 36 inches for larger openings, but they are less common for interior applications.

What are the disadvantages of a Prehung door?

• Some disadvantages of Prehung doors include the potential for misalignment during installation, the need for precise measurements, and the weight of the entire assembly, which may require extra support during installation.

Is it cheaper to buy a Prehung door?

• Prehung doors are often more expensive than door slabs, but they can save on installation costs because they come preassembled with the frame and hardware.

Is it easier to hang a Prehung door or a slab door?

• Hanging a Prehung door is typically easier for DIYers because it includes the frame and hardware, simplifying the installation process.

How much out of plumb is acceptable?

• Generally, a maximum out-of-plumb measurement of 1/4 inch over an 80-inch height is considered acceptable for doors.

How far should framing be from the wall?

• Framing should be flush or slightly inset from the wall surface to allow for drywall or other finishing materials.

Is professional framing worth it?

• Professional framing can ensure structural integrity and precise measurements, making it worth the cost for many construction projects.

Will a 30-inch door fit in a 32-inch opening?

• Yes, a 30-inch door can fit in a 32-inch rough opening with the proper framing and adjustment.

What size door do I need for a 30-inch rough opening?

• For a 30-inch rough opening, you would typically use a 28-inch wide door.

Is a 28-inch door too small for a bedroom?

• A 28-inch door may be considered narrow for a bedroom, and it may not meet accessibility or building code requirements in some areas.

How big should a rough door opening be?

• A rough door opening should be about 2 inches wider and 2.5 inches taller than the nominal size of the door you plan to install.

Does rough in size matter?

• Yes, the rough-in size matters as it determines whether the door will fit properly and function correctly once installed. It’s essential to match the rough-in size to the door size you intend to use.