DIY Calculators OnlineHow the studs are counted
Studs go every 16" or 24" along the wall, plus one at the end. Each door or window adds about three studs: two jack studs that carry the header and one extra king stud. Each corner adds two studs so the inside wall has something to nail drywall to.
studs = ⌈length × 12 ÷ spacing⌉ + 1 + 3 × openings + 2 × corners
Cripple studs above and below windows usually come out of offcuts. Add a few spare studs for warped boards and blocking.
Precut stud lengths
Lumber yards sell studs precut for a single bottom plate and a double top plate. The extra 1 1/8" leaves room for ceiling drywall and finished flooring.
| Wall height | Precut stud | Framed height |
|---|---|---|
| 8 ft | 92 5/8" | 97 1/8" |
| 9 ft | 104 5/8" | 109 1/8" |
| 10 ft | 116 5/8" | 121 1/8" |
Headers
A header is two 2× boards on edge with a 1/2" plywood spacer, which makes it as thick as a 2×4 wall. It is 3" longer than the rough opening so each end sits on a jack stud. Header depth depends on the opening width and the load above. Check the header tables in IRC R602.7 for load-bearing walls.
Questions
How many studs for a 12 ft wall?
At 16" on center, 10 studs on layout. With one door and two corners, about 17.
Should I subtract openings from sheathing?
The calculator doesn't. Cutouts are rarely reusable, and the spare covers mistakes.
16" or 24" on center?
16" is standard and makes walls stiffer. 24" saves lumber and is allowed for many 2×6 walls, but check your code and the sheathing's span rating.