How to Calculate Door Frame
What is Door Frame?
A door frame calculator helps estimate the timber or steel needed to frame a doorway opening, including the rough opening size (door size + clearance), lintel requirements, and stud placement.
Step-by-Step Guide
- 1Rough opening = Door width + 50mm clearance (25mm each side) × Door height + 25mm head clearance
- 2Standard door: 838mm wide × 1981mm high; rough opening: ~888mm × 2006mm
- 3Lintel span load depends on whether the wall is load-bearing
- 4Trimmer studs (jack studs) run full height; king studs run from floor to header
Worked Examples
Input
Standard 838mm door · non-load-bearing partition wall
Result
Rough opening 888×2010mm · 50×100mm timber frame
Add cripple studs above header