Rough Openings | Standard Framing Dimensions

By Todd Fratzel on Framing

Standard Window Rough Openings

Window rough openings are framed in a similar way to door openings. Again I like to use examples so let’s say we’ve got a 3′ wide by 4′ tall window unit then the rough opening would be 38-1/2″ wide and 50-1/2″ tall. Now, most window manufactures actually specify a standard rough opening which is typically a bit tighter so it’s best to follow the manufacturers recommendations when possible.

As I mentioned above with reference to doors, the window header height will typically match the doors which is 82-1/2 inches for a 6/8 door. The jack studs end up the same as the door jack studs and the cripple studs can then be calculated by subtracting the window rough opening height from the jack stud height minus an additional 1-1/2″ for the sill plate.

Non-Standard Rough Openings

The rules above work well for most standard windows and doors. However, you’ll need special rough openings for:

Good luck framing and remember to keep your openings square!!

About the author

Todd Fratzel

I'm full time builder for a large construction company in New Hampshire. I run their design-build division that specializes in custom homes, commercial design-build projects and sub-divisions. I'm also a licensed civil and structural engineer with extensive experience in civil and structural design and home construction. My hope is that I can share my experience in the home construction, home improvement and home renovation profession with other builders and home owners. I'm also the Editor-in-Chief and Founder of Tool Box Buzz. Please feel free to contact me if you have any questions, suggestions or you'd like to inquire about advertising on this site.

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51 Comments

  1. Brooks says:

    This site is very helpful for those of us who don’t do this every day. Thank you for making it available.

    • Todd says:

      Brooks – Thanks for the compliment. I hope you come back often for more advice and information.

      • Wimal Lokuliyana says:

        Thank you Todd!
        The simple way of explaining without long descriptions is appreciated. Anybody can understand easily. Very useful.
        Wimal Lokuliyana

  2. deshgaurav says:

    plz enter the standard size of door and window.

  3. dennis says:

    If i am building an addition when i stand my wall up it is 1 inch higher than the old wall can i make the cornish even by making my new rafters with a longer overhang,

  4. rick hudson says:

    Your web site says window rough opening should be 2 1/2″ over actual. The flange on window is not that large, so i respectfully suggest your info is wrong. !/2 ” to 3/4 is what I use. Did I miss something, Thanks, Rick

    • Todd says:

      Rick,

      Here’s what the article says:

      “Window rough openings are framed in a similar way to door openings. Again I like to use examples so let’s say we’ve got a 3′ wide by 4′ tall window unit then the rough opening would be 38-1/2″ wide and 50-1/2″ tall. Now, most window manufactures actually specify a standard rough opening which is typically a bit tighter so it’s best to follow the manufacturers recommendations when possible.”

      As I noted, some manufacturers use a tighter dimension. 2-1/2 inches is the industry standard, many window manufacturers adjust after framing. Framing usually happens, then windows are ordered based on rough-openings.

      • Cody says:

        I think what he was meaning by 2 1/2″ wider than the windows was 2 1/2″ larger than the actual window pane itself. Just like a door, a 3’0″ door is only 36″, but once you add the jamb thickness and the space between the door and jamb, you actually have more like 37 3/4″. Same goes with windows, if you want an actual window pane, let’s just say 24″ wide, then once you allow for the frame, and insulation, you would end up being 2 1/2″ over. Just how I understood, I hope I didn’t confuse the topic more than it was. ?

  5. grandpa bear says:

    will the rough opening for a double door still be the nominal dimensions + 2.5 inches in both height and width?

    • Todd says:

      Yes sir :) However, if you have certain special doors that number might change, some outswing French doors and some Andersen units are different so check the spec with the door.

  6. Troy says:

    We are building a small workshop with just a plain concrete floor. With no subfloor going in, and thus no finish flooring, what is the measurement to use on this type of door application for roughing in?

    • Todd Fratzel says:

      Troy – Typically we’ll make that rough opening another 3″ wide so we can attach a pressure treated buck in the opening so there’s something to shim/attach the door framing. Good luck.

  7. MT Acres says:

    Good Day Todd

    Your site has been very helpful, and I plan to visit it more in the future.

    Question: when framing a rough opening for a man door for a shop, do I still require the bottom plate or do I make my measurement minus the bottom plate.

    • Todd Fratzel says:

      The height is from the floor surface to the bottom of header. Depending on the number of plates you’ll need to consider that.

  8. cheryl says:

    would like to install a standard size exterior door on a wall that is 84″ to the bottom of the ceiling studs. The 2 2×4’s in the ceiling. Is there enough space?

    • Todd Fratzel says:

      Cheryl,

      It really depends on if that’s a bearing wall, and if so, how much structural support is required above the door. 84″ is only 1-1/2″ above the top of the rough opening for a 6’8″ door. That basically doesn’t leave any room for a structural header.

  9. JOE FLORES II says:

    Helped me refresh my memory. Thank you very much.

  10. Phaidra says:

    We are building a greenhouse and bought old windows and doors. We are considering installing the windows and doors without jambs since they did not come with them and we can use the 2×4 framing to screw the hinges into. Does the 2-1/2″ include the jamb? If I don’t have a jamb? Should I just go with 1/2″ wider and longer when framing?

    • Todd Fratzel says:

      Great question! 1/2″ will likely work well with no jambs. You’ll need to install jamb stops but that clearance will probably work pretty good. Certainly no smaller, and up to 3/4″ would be better. Good luck.

  11. Ken Sapp says:

    In installed some M&W windows many years ago. Most were 3/0 X 4/6. I framed a 38 X 58 rough opening. Windows fit fine. But the newer windows with an attachment flange don’t seem to need the extra two inches of height in the opening. Is that correct?

    • Todd Fratzel says:

      We still frame that way today. The extra opening definitely helps ensure that all the windows can be properly plumbed and leveled.

  12. Steve Apple says:

    my son bought a brick home built in the 50’s and needs to replace windows. I measured the outside of the window box at 36 5/8 x 55 3/4, 30 3/4 x 47 1/4 and the last 54 x 52 3/4 can these be replaced with any standard window or does he have to buy special. All the measurements were with the molding removed and to the outside of the window box frame. Thank you

    • Todd Fratzel says:

      Most vinyl window companies that I work with make each window to order, so there’s really not a “special” order. We just give them the dimensions and they make what we need.

  13. kimberly says:

    I have a window that is 34×60.5 what will the rugh opening be? will I add 2.5 o the height and width?

  14. David Webb says:

    I am going to put up a steel building for a garage and living quarters. If I want to use wood doors, how would that normally be done on a steel (commercial type) building? No carpet, no tile. Also I will be using several 3/0, 8/0 solid windows. Does that pose a problem. The building mfg says they can make the openings any size, but I am wondering about mounting. Thanks, David

    • Todd Fratzel says:

      Not an issue, you’ll want to have the rough openings made a bit larger so you can install a wood “buck” which is wood framing attached to the steel, so you can install the windows to the wood framing.

  15. Martha says:

    just trying to replace a middle frame on an interior door. don’t want to buy in bulk.

  16. Sylvia says:

    If there’s a window rough opening in a wall plate can it be sealed or covered if we don’t want a window there?

  17. Bob says:

    I am trying to accommodate furniture, some of which is 42″high. I am trying to maximize window height and am assuming 36+ will accommodate that height with a slight reveal between the furniture and the sill.

    Do you have any advise>

  18. Andy says:

    Hi I am about to build a camp. why is it necessary to use birds mouths. I could use t30 structural screw. I have an engineering background and know the X portion of compression will be off set by tension… but old school carpenters give a bad look with this idea.

  19. Derek says:

    I also think this info is misleading. I quickly googled rough in gap and this article popped up first. Unfortunately I’m now a full 2 inches larger RO than my window requires.

    • Todd Fratzel says:

      Derek

      Well that depends, are you installing new windows with frames or replacement windows, there is a HUGE difference. These RO’s are standard for new construction here in the Northeast.

  20. When enclosing an open porch with windows and doors, can the framing be 3″ between door and windows? We would want it to look like sunroom?
    Thanks
    Ron

    • Todd Fratzel says:

      not sure I understand the question. For a screen porch it depends on the type of door you’ll be using.

  21. Bill Wood says:

    For a 3-0x6-8 door shouldn’t the header height be 81-1/4 AFF?
    This allows for the door opening (80″), + jamb (3/4″), and
    clearance (1/2″) It seems 82-1/2″ would be too tall to allow
    fastening of the top door trim.

    • Todd Fratzel says:

      Bill….thousands of homes built in this area with 82-1/2″….never too tall with ONE exception….outswing french doors…those are shorter.

  22. Ed says:

    I have a question in your statement, “82-1/2 inches also happens to be the standard “header height” for windows and doors. If you’re a novice framer then this is the height of the BOTTOM of the window and door headers. This is also the top of the jack studs. Which means the jack studs are 81 inches long (typically).”
    If 82-1/2 inches is the bottom of the header, and 81 inches is the height of the Jack stud, why is there a difference of 1-1/2 inches. I’m confused.

    • Todd Fratzel says:

      Because there is a bottom plate that is 1-1/2″ thick, add the jack stud and you’ll be at 82-1/2″ :)

  23. cheryl dumas says:

    I’ve got a R/O of 36×50. What will my actual window size be?

    • Todd Fratzel says:

      Hard saying actually..there is no standard. Each manufacturer does it a bit different, but they all typically fit into a RO.

  24. Sam says:

    Hi Todd, I’m putting in a couple of large (144” wide x 72” tall) casement Windows in a new room. The roof is pretty high up (11’). How large a beam do I need to use for the upper frame and lower frame ? I guess the upper beam will be holding a lot of the weight of everything above and so should be bog enough to not transfer any weight down on the window frame. Is a 2”x6” beam sufficient to frame it ? All around ?

    • Todd Fratzel says:

      Sam – 2×6 is not sufficient anywhere. The size will depend on the loading, where you live, local codes. But a 12′ wide window will need a very deep header.

  25. Joann Palmer says:

    If the rough opening height is 82 inches, is there any possible way to make an 82-inch tall door and frame work? If not, can I cut the bottom 2 inches off the header?

  26. Woody says:

    Not everyone knows door terminology so it needs to be clear that standard sizes of doors are typically based off the slab or panel size and does not include the frame components. The “door” or “unit” size is what you need to understand to create the rough opening. The adding of the 2 1/2″ number being referenced is based off the slab or panel size plus the frame components. If you have a special frame that is thicker than most standard door frames you would need to adjust your rough opening.

  27. Lori Duval says:

    Installing a pre-hung bay window with the following dimensions: interior height from top of board to bottom of board is 33 1/2, exterior height is 35 on side facing inside house, 36 1/4″ height on side facing out. Width is 60″ on the side facing inside, 61 1/2″ on the side facing outside. Installing where there was no window before. What should my rough opening be? Confused with different measurements front to back.

  28. John says:

    Thinkin the rough opening figures are bfore the jack studs are installed??

  29. Robert Stutesman says:

    Sorry but I’ve been framing for 25 years and my windows are framed to the exact size of window. A 3’0 x 4’0 should be framed at 36” wide and height is 48” because the windows are exactly a 1/2” smaller than the actual size.. maybe I’m confused with your answer? But that’s how we’ve always done it

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