Standard Door Sizes

Nearly every door in an American house is 80 inches tall. What changes is the width, and it changes in 2 inch steps from a 24 inch closet door to a 36 inch entry. Those dimensions matter twice: once when you're ordering, and again when you're working out how much wall you actually have to cover, since every door is square footage you don't paint or board.

Standard sizes

Interior doors come in widths of 24, 28, 30, 32, or 36 inches, at a standard height of 80 inches. A single exterior door is normally 36 by 80.

Door	Width	Height	Where it's used
Closet or pantry	24 in	80 in	Reach-in closets, small utility spaces
Small interior	28 in	80 in	Closets, tight hallways
Standard interior	30 in	80 in	Bedrooms, offices
Wide interior	32 in	80 in	Bathrooms, accessible routes
Extra wide interior	36 in	80 in	Primary suites, laundry, accessible routes
Exterior entry	36 in	80 in	Front and back doors
Patio slider (2 panel)	72 in	80 in	Rear elevations

Eighty inches is 6 feet 8 inches, which is where the "six-eight" in a builder's shorthand comes from. Taller options exist at 84 and 96 inches, and they turn up in houses with 9 or 10 foot ceilings, where a standard door looks squat. Standard ceiling height covers when that happens.

Rough openings

The rough opening is the hole in the framing, and it's bigger than the door so the prehung unit can be shimmed plumb. The shop rule for a prehung interior door is the slab width plus 2 inches and the slab height plus about 2.5 inches.

Door slab	Rough opening
24 x 80 in	26 x 82.5 in
28 x 80 in	30 x 82.5 in
30 x 80 in	32 x 82.5 in
32 x 80 in	34 x 82.5 in
36 x 80 in	38 x 82.5 in

Measure your actual opening before ordering rather than trusting the plan. Framing moves, and a quarter inch decides whether the unit goes in.

Code minimums

The residential code says surprisingly little about interior doors. There's no minimum width for a bedroom or bathroom door at all. What it does require is one proper way out:

The egress door must provide a clear width of at least 32 inches, section R311.2.
Its clear height must be at least 78 inches, measured from the threshold to the bottom of the stop.
At least one such door is required from each dwelling unit, and it has to be side-hinged.

Note the word clear. A 32 inch door slab does not give 32 inches of clear width once the stop and the open door leaf intrude, so the egress door is normally a 36 inch unit. The same distinction applies to accessibility: the ADA clear width of 32 inches is measured with the door open at 90 degrees.

Door square footage, for wall estimates

This is where door sizes meet area. When you're estimating paint, wallpaper, siding, or paneling, you subtract the openings from the gross wall area, so you need each door's area.

Door	Size	Square feet
Closet door	24 x 80 in	13.3 sq ft
Small interior	28 x 80 in	15.6 sq ft
Standard interior	30 x 80 in	16.7 sq ft
Wide interior	32 x 80 in	17.8 sq ft
Entry or wide interior	36 x 80 in	20.0 sq ft
Double or patio slider	72 x 80 in	40.0 sq ft
Single garage door	9 x 7 ft	63.0 sq ft
Double garage door	16 x 7 ft	112.0 sq ft

Estimators often round a standard door to 21 square feet rather than 20, which accounts for the frame and casing around the slab. Either figure is fine for paint. For drywall, most installers don't subtract interior doors at all, because the board is hung over the opening and cut out afterward. The wall calculator applies the right treatment for each job, and the paint calculator uses the deduction to work out gallons.

A garage door is the one opening you should never skip. At 63 or 112 square feet it's a large share of that wall.

Common mistakes

Ordering to the rough opening. The door is the slab size. The rough opening is 2 inches wider.

Assuming the door slab gives you its width in clearance. A 32 inch door gives about 30 inches of clear passage once it's hung, which is why egress and accessible routes usually need a 36 inch unit.

Subtracting doors from a drywall estimate. Board goes over the opening and gets cut out. Subtract for paint and siding, not for drywall.

Measuring the door you're replacing instead of the opening. If a previous owner planed a door to fit a racked frame, you'll order the wrong size.

Forgetting that swing needs floor. A 3 foot door sweeps about 7 square feet of floor as it opens, which matters in small bathrooms and offices.

Frequently asked questions

What is the standard door size?

Interior doors are 80 inches tall with widths of 24, 28, 30, 32, or 36 inches. A standard interior door is 30 by 80, and a standard exterior entry door is 36 by 80.

What is the standard interior door size?

30 by 80 inches for bedrooms and offices, and 32 by 80 for bathrooms and wider passages. Closet doors are commonly 24 or 28 inches wide.

What is the rough opening for a 30 inch door?

32 inches wide by about 82.5 inches tall. The general rule is the slab width plus 2 inches and the height plus about 2.5 inches, which leaves room to shim the frame plumb.

How tall is a standard door?

80 inches, or 6 feet 8 inches. Homes with 9 or 10 foot ceilings sometimes use 84 or 96 inch doors so the proportions look right.

What is the minimum door width by code?

There is no minimum for ordinary interior doors. The required egress door must give at least 32 inches of clear width and 78 inches of clear height, which in practice means a 36 inch door.

How many square feet is a door?

A standard 36 by 80 inch door is 20 square feet. A 30 by 80 interior door is 16.7 square feet. Estimators often round to 21 square feet for a standard door to include the frame.

Do I subtract doors when calculating wall square footage?

For paint, wallpaper, siding, and paneling, yes. For drywall, usually not, since the board is hung over the opening and cut out, and the offcut is waste anyway. Always subtract a garage door.