Add 2.5 inches each direction to the size of the door. So, a 3 0 x 6 8 would be 38 1/2" x 82 1/2".
38" it's actually 82 3/4" high and 38" wide
Remember 36" is the width of you door slab. If you can measure the door you want to frame in then take the measurement and add 3/4" to it so you can still have room on the side to shim it properly. If you don't have the door but know which one you want, go to the store and the door will normally have the rough opening size on the label.
standard height door (80" tall) 2' 6" wide door. Rough opening width is oversized 2"
Rough opening requirements vary by door manufacturer. It would be best to check with the lumberyard where you plan to purchase the door, but if you've got to get it framed now, make it 38-1/2" wide, and 6'-11" high. You can always build it in later if necessary.
Add two inches to height and width. So a 36 x 80 door roughed out is 38 x82. This is with doors only. Windows you add 1 inch to the height and width.
The recommended rough opening size for a 30 by 80 inch door is 32 by 82 inches.
The rough opening required for a 30-inch door is typically 32 inches in width and 82 inches in height.
The recommended rough opening size for a 30-inch door is 32 inches in width and 82 inches in height.
The recommended rough opening size for a 34-inch door is 38 inches in width and 82 inches in height.
The recommended rough opening size for a 24-inch door is 26 inches in width and 82 inches in height.
The recommended rough opening size for a 28-inch door is 30 inches in width and 82 inches in height.
The recommended rough opening size for a 30-inch interior door is 32 inches in width and 82 inches in height.
The standard rough opening size required for a 30-inch door is 32 inches in width and 82 inches in height.
The standard rough opening size required for a 24-inch door is 26 inches in width and 82 inches in height.
The standard rough opening size required for installing a 30-inch interior door is 32 inches in width and 82 inches in height.
The rough opening width for a 24" door is 26-1/2" The rough opening height for a 24" door is 26-5/8" Rough openings are 2" wider and 2-1/2" taller than the actual door. This allows room for the door frame and adjustment.
+ 2 1/2" each way.