Framing calculator
Studs, plates and headers for a wall with doors and windows, plus a stud spacing check against the IRC.
Studs to buy
36 2x4 × 8 ft
- Stud length (cut)
- 91 1/2 in
- Layout studs
- 16
- Studs before extra
- 32
- Plates
- 60 ft (5 × 16 ft)
- Header pieces
- 6 (19.8 ft)
- Cripples
- 10
- Window sills
- 6.0 ft
- Estimated lumber cost
- 16 in on center (IRC maximum 24 in) The IRC table doesn't allow 2x4 studs for this load: use 2x6 or have it engineered
- 8.0 ft wall (IRC maximum 10 ft between supports)
- The openings and their studs are wider than the wall.
Headers and jack studs are counted, not sized: size them from the IRC header tables. Layout studs that land in an opening are cut into cripples.
How to figure studs for a wall
Lay studs out from one end of the wall at the spacing you choose, so sheathing and drywall edges land on a stud, then add the extra framing around each opening and at corners.
- Layout studs = wall length (in) ÷ spacing, rounded up, + 1 for the end
- Openings: + 4 studs each (a king and a jack stud on both sides). Layout studs that land in the opening are cut into cripples above the header and, for windows, below the sill.
- Corners and intersections: + 2 studs each
- Stud length = wall height − 3 plates (a single bottom plate and a double top plate)
- Plates = 3 × wall length; headers = 2 pieces per opening, each the opening width + 3 in
Worked example
A 20 ft wall, 8 ft tall, with studs at 16 inches: 240 ÷ 16 = 15, + 1 = 16 layout studs. One 38 in door and 2 windows add 4 × 3 = 12 studs, and 2 corners add 4: 32 studs in all, each cut to 91 1/2 in from 8 ft boards. The plates take 3 × 20 = 60 ft of lumber, and the three headers take 6 pieces (19.8 ft).
Stud size, height and spacing (IRC Table R602.3(5))
From IRC Table R602.3(5), as reproduced in the City of Grand Rapids (MN) Basic Wood Framing handout (2015 Minnesota State Building Code). Maximum spacing in inches on center; a dash means the size isn't allowed for that load. Local codes amend these, so check with your building department.
| Studs | Roof only | 1 floor + roof | 2 floors + roof | 1 floor only | Bearing height | Nonbearing |
|---|---|---|---|---|---|---|
| 2x4 | 24 in | 16 in | — | 24 in | 10 ft | 24 in, 14 ft |
| 2x6 | 24 in | 24 in | 16 in | 24 in | 10 ft | 24 in, 20 ft |
Heights are distances between points of lateral support. A habitable attic on 2x4 studs is limited to a 32 ft roof span; past that, use 2x6 or an engineered design.
Studs for a plain wall by length
8 ft wall, no openings, corners or extra.
| Wall length | 12 in on center | 16 in on center | 24 in on center | Plate lumber |
|---|---|---|---|---|
| 8 ft | 9 | 7 | 5 | 24 ft |
| 10 ft | 11 | 9 | 6 | 30 ft |
| 12 ft | 13 | 10 | 7 | 36 ft |
| 16 ft | 17 | 13 | 9 | 48 ft |
| 20 ft | 21 | 16 | 11 | 60 ft |
| 24 ft | 25 | 19 | 13 | 72 ft |
| 30 ft | 31 | 24 | 16 | 90 ft |
Wall framing questions
What is the standard stud spacing?
16 and 24 inches on center are the usual layouts, because sheathing and drywall edges land on the studs. Under IRC Table R602.3(5), 2x4 studs can be 24 inches apart when they carry only a roof and ceiling, but no more than 16 inches when they also carry a floor, and 2x4s can't carry two floors at all. The table above has every case; follow your local code.
How many studs do I need for a 12 ft wall?
10 at 16 inches on center or 7 at 24 inches, before doors, windows and corners. Each door or window adds 4 studs, each corner 2 more, and the calculator adds the extra you choose for warped or split boards.
How do I frame a door or window opening?
Each side of the rough opening gets a full-height king stud with a shorter jack (trimmer) stud nailed to it; the jacks hold up the header across the top. Layout studs that would land in the opening are cut short as cripples above the header, and for a window, below the sill. Wide openings in bearing walls may need two jack studs per side; the IRC header tables say how many.
What size header do I need?
It depends on the opening width, what the wall carries and the building width. The IRC header span tables (Tables R602.7(1) to R602.7(3)) list the size and number of jack studs for each case. This calculator counts the header pieces but doesn't size them; for anything beyond the tables, use an engineered header and a qualified professional.
How long are the studs for an 8 ft wall?
With a single bottom plate and a double top plate (3 × 1 1/2 in), the studs are 91 1/2 in long, so the wall framing stands 8 ft. If you buy precut studs, check their length against your plates and ceiling finish.