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Door rough opening calculator
Door size to the framed rough opening for prehung, pocket and barn doors.
Prehung doors
The rough opening is usually the door width plus 2" and the height plus 2" to 2-1/2". A 32" by 80" door needs about a 34" by 82-1/2" opening. That leaves room for the jamb and shims to set the door plumb.
Pocket doors
A pocket door slides into the wall, so the rough opening is roughly twice the door width plus an inch. The pocket side of the wall cannot hold plumbing, wiring or ducts.
Barn and bypass doors
A barn door hangs on a track outside the wall and overlaps the opening about an inch on each side. Leave clear wall about twice the door width so it can slide fully open.
Common questions
What is the rough opening for a 36 inch door?
About 38" wide by 82-1/2" high for a standard 80" prehung door.
How wide should a door be for a wheelchair?
A 36" door gives about 32" to 34" of clear passage, which meets accessibility guidance. A 32" door gives about 30".
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