How much space should be allowed between studs to allow for a door?

For example, if the finished door has a 30" opening, then what should be the distance between the framing studs that enclose the door?

1 Answer 1


Normally rough opening is 2 inches larger then the nominal door size. This leaves approximately 1/4" on each side for shimming to plumb.

Some carpenters prefer 2-1/2", leaving a 1/2" gap for shimming. In case framing isn't very precise (say when using unskilled volunteer labor), 1/4" can sometimes be inadequate.

  • This would vary from an interior to an exterior door, no?
    – JPhi1618
    Feb 25, 2019 at 18:50
  • 1
    I've installed a few exterior doors but I never have really given it much thought as to what the rough opening "should" be, I imagine it's the same. There are other things to consider like how thick or deep the casing is going to be and the different finish material inside and outside. I'm actually curious if there is a standard that's different.
    – Joe Fala
    Feb 25, 2019 at 18:58
  • @horta , been there; done that. When I do, I'll delete that comment if I don't think it's representative of my normal level of understanding. Feb 26, 2019 at 10:33

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