How to Measure a Rough Opening

Measure Your Entryway - for Prehung Units Only

  1. To ensure accurate measurements, first remove the interior casing on the sides and top of your single or double door to reveal rough opening frame.

  2. Measure from inside the face of one stud to inside the face of the other stud and write down the measurement.

  3. Measure from the subfloor (plywood or concrete) to the bottom of the header above the door and write down the measurement.
    Measurement B:_________ Measurement C:__________

Configuration Actual Size Rough Opening
6/8 Single 3/0 Door Door:
3/0 x 6/8 =35-3/4” X 79-1/4”
3/6 x 6/8 =41-3/4” X 79-1/4”

Sidelite:
1/0 x 6/8 = 11-7/8” x 79-1/4”
1/2 x 6/8 = 13-7/8” x 79-1/4”
38-3/8” X 82-1/2”
Single 3/6 Door 44-3/8” X 82-1/2”
Single 3/0
One 12” sidelite
51-7/8” X 82-1/2”
Single 3/0
One 14” sidelite
53-7/8” X 82-1/2”
Single 3/0
Two 12” sidelites
65-3/8” X 82-1/2”
Single 3/0 
Two 14” sidelites
69-3/8” X 82-1/2”
Double 3/0 Door 74- 7/8” X 82-1/2”
7/0 Single 3/0 Door Door:
3/0 x 7/0 =35-3/4” X 83-1/4”
3/6 x 7/0 =41-3/4” X 83-1/4”

Sidelite:
1/0 x 7/0 = 11-7/8” x 83-1/4”
1/2 x 7/0 = 13-7/8” x 83-1/4”
38-3/8” X 86-1/2”
Single 3/6 Door 44-3/8” X 86-1/2”
Single 3/0
One 12” sidelite
51-7/8” X 86-1/2”
Single 3/0 
One 14” sidelite
53-7/8” X 86-1/2”
Single 3/0 
Two 12” sidelites
65-3/8” X 86-1/2”
Single 3/0 
Two 14” sidelites
69-3/8” X 86-1/2”
Double 3/0 Door 74- 7/8” X 86-1/2”
8/0 Single 3/0 Door Door:
3/0 x 8/0=35-3/4” X 95-1/4”
3/6 x 8/08 =41-3/4” X 95-1/4”

Sidelite:
1/0 x 8/0 = 11-7/8” x 95-1/4”
1/2 x 8/0 = 13-7/8” x 95-1/4”
38-3/8” X 98-1/2”
Single 3/6 Door 44-3/8” X 98-1/2”
Single 3/0 
One 12” sidelite
51-7/8” X 98-1/2”
Single 3/0 
One 14” sidelite
53-7/8” X 98-1/2”
Single 3/0 
Two 12” sidelites
65-3/8” X 98-1/2”
Single 3/0
Two 14” sidelites
69-3/8” X 98-1/2”
Double 3/0 Door 74- 7/8” X 98-1/2”

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