Choosing the right size for your iron door is as important as selecting the design. Unlike standard doors, wrought iron entry doors are heavy architectural elements that require precise measurements for proper installation, operation, and long-term performance.
This guide will help you:
Correctly measure your rough opening
Understand iron door sizing
Learn how jamb dimensions affect installation
Avoid common measuring mistakes
Door Net Frame Size, Rough Opening Size, and Jamb Size
First: Rough Opening Size Confirmation
To accurately measure a rough opening, remove the trim or casing around the door or window, then measure the width between the studs(or sides of the opening) and the height from the subfloor to the bottom of header.
If you are replacing the old door, and want to confirm the rough opening without removing the door, you can measure it brick to brick to get the rough opening size.
Second: Confirm The Iron Door Size
All the wrought iron doors are pre-hung, therefore, the door size indicated will be the net frame size, including the jambs and threshold.
To achieve a proper installation, pls leave at least 1" in width and 1/2" in height installation gap based on the rough opening.
For example, if you want to make the door net frame size 60x96, then the rough opening size should be at least 61x96.5.
Size Table
| Door Net Frame Size | Rough Opening (at least) |
| 36x81 | 37x81.5 |
| 48x96 | 49x96.5 |
| 60x81 | 61x81.5 |
| 72x96 | 73x96.5 |
Third: Which Jamb Size Should I Choose?
1. Measure Your Wall Thickness
Measure from drywall to drywall (or exterior sheathing if exposed).
Common wall thicknesses:
2×4 wall = 4.5" (3.5" stud + ½" drywall each side)
2×6 wall = 6.5" (5.5" stud + ½" drywall each side)
Masonry/block walls = 6"– 8+" (varies)
2. Choose the Correct Pre-Hung Jamb Size
| Jamb Size (Width) | Designed for Wall Thickness | Common Wall Type | |
|---|---|---|---|
| 4-9/16" | 4.5" (4-1/2") | 2×4 stud walls (3.5" stud + ½" drywall each side) | |
| 6" | 5.5"–5-7/8" | 2×6 stud walls without drywall, or thin sheathing | |
| 6-9/16" | 6.5" (6-1/2") | 2×6 stud walls (5.5" stud + ½" drywall each side) |
The common mistakes while you are confirming the door size.
1. The door size is for the door slab only. (x)
The door size indicated on our website is the net frame size, including the frames/jambs and threshold if there is one. If the door has a transom above or the sidelights, the size also includes the frame.
2. No installation gap leaving for the door unit. (x)
Pls leave at least 1" in width and 1/2" in height for the installation gap. Therefore, the rough opening size should be at least 1" wider and 1/2" taller than the door net frame size.
3. The jamb size is not important. (x)
If the jamb is too small, the framing or rough opening may be exposed.
If the jamb is too large, it will need to be trimmed and fitted to the wall.
Of course, Elite Custom Door will verify all the measurements with you before production. And the CAD drawing will be provided for approval, to avoid any mistakes.
If you have any questions, pls contact us at info@elitecustomdoor.com.
