Standard Door Rough Opening
The size will be varying on the wooden species and the door’s thickness. If you want to measure the rough opening for your door you will have to add two inches to the width then it will easily fit into the typical opening for an internal door.
After that, you will have to add two and a half inches to your door’s height. The width calculating formula is Your Door’s Inches + 2 inches (width) = Rough Door Opening.
The height calculating formula is Your Door’s Inches + 2 and ½ inches (tall) = Rough door opening.
Also, Read: Top 5 Cement in India
Rough Opening for 24 Inch Door
By adding 2 inches to the width, you get the rough opening size for 24 inches door.
So, for 24 inches door, the rough opening size will be 26 inches.
Rough Door Opening for 28 Inch Door
Similarly, after adding 2 inches to the width, you will get the rough opening for a 28 inches door.
30 inches will be the rough door opening width for a 28 inches door.
Also, Read: How to Calculate Steel Quantity
What Is Rough Opening for a 24 by 80 Inch Door?
For a standard door having a width of 24 inches width and a height of 80 inches the space required for a rough opening required for you will be a width of 26 inches and a height of 82.5 inches for a snug fit.
What Is Rough Opening for a 28 by 80 Inch Door?
If you have a standard door of 28 inches in width and a height of 80 inches then the rough opening required for you will be the width of 30 inches along with the height of 82.5 inches.
This is so because in a standard door of 28 inches the width of the rough opening must be 2 inches extra along with the extra height of 2 and a half inches.