Stud and wall framing calculator

A materials count for one straight stud wall: layout studs, the extra studs at doors, windows and corners, plates and header stock. Run it once per wall and add the results up.

Full-length studs to buy

20 studs counted, plus 10% for bowed, twisted or miscut pieces. Plates: 3 × 16 ft boards for 42 ft of bottom and double top plate. Headers: 13.3 ft of header stock.

Item	Count	How it is counted
Layout studs	12	one every 16 in, plus one at the far end
Inside openings	−4	layout studs that fall in a rough opening
King studs	+4	two per opening, full height
Jack (trimmer) studs	+4	two per opening, carrying the header
Corner studs	+4	2 extra per corner
Studs counted	20
Cripples (short)	9	above headers and below sills, usually cut from offcuts

How the count works

The calculator follows conventional platform framing: a single bottom plate, a double top plate, and studs on a regular layout from one end of the wall. Each part of the count is shown separately in the result so you can check it against your plans.

Layout studs: ceil(wall length / spacing) + 1. One at the start, one at every multiple of the spacing, and one at the far end.
Openings: each door or window adds two full-height king studs and two jack (trimmer) studs that carry the header. The layout studs that would have stood inside the rough opening, floor(opening width / spacing) of them, are subtracted.
Corners and intersections: the extra studs per corner you choose, and two per place where a partition wall meets this one, for drywall backing.
Cripples: short studs above each header, and above and below each window sill, one per layout position across the opening. They are listed separately because they are usually cut from offcuts.
Plates: three times the wall length, in the stock length you choose. Header stock: two plies per opening, each the opening width plus 3" for 1 1/2" of bearing on each jack.

Worked example

The default is a 14 ft (168") exterior wall at 16" on center with a corner at each end, a door with a 38" rough opening (a 36" door) and a window with a 36" rough opening.

Layout: 168 / 16 = 10.5, rounded up to 11, plus 1 = 12 studs
Openings: 4 kings and 4 jacks, minus 2 layout studs inside each opening: +8 − 4
Corners: 2 corners × 2 extra = +4

That is 20 full-length studs, and 22 with 10% extra for studs too bowed or twisted to use. Plates are 42 ft, three 16 ft boards; header stock is 2 × (38 + 3) + 2 × (36 + 3) = 160", about 13.3 ft; and the two openings need 9 cripples, cut from offcuts.

Layout studs for plain walls

Wall length	16" on center	24" on center
8 ft	7	5
10 ft	9	6
12 ft	10	7
14 ft	12	8
16 ft	13	9
20 ft	16	11
24 ft	19	13

No openings, corners or waste; add those from the calculator above.

Precut stud lengths

Studs are sold precut so that, with a single bottom plate and a double top plate (4 1/2" of plates in total), the framed wall is a little over a whole number of feet. That leaves room for a full sheet of drywall plus a gap.

Wall	Precut stud	Framed height
8'	92 5/8"	97 1/8"
9'	104 5/8"	109 1/8"
10'	116 5/8"	121 1/8"

Where it stops being reliable

This is a materials estimate, not a structural design. It does not size headers, decide how many jacks a wide opening needs (openings over about 6 ft often need two per side), place fire blocking, or handle rake walls, point loads and hold-downs. Those are set by your plans and your local building code, and a building inspector or engineer is the right person to ask. It also assumes the layout starts at one end of the wall; if your layout is continued from an adjoining wall, positions and dropped-stud counts can shift by one.

Common questions

What is the quick rule for studs in a wall?

At 16 inches on center, about one stud per foot of wall covers the layout studs plus a little extra, which is why the "one per foot" rule of thumb survives. It undercounts walls with several openings and corners. Counting openings and corners separately, as this calculator does, is more reliable.

Why does a wide opening not add many studs?

Because the layout studs that would have stood inside the rough opening are no longer needed at full height. A 72-inch opening at 16 inches on center removes four layout studs and adds two kings and two jacks, so the full-length count barely changes. Those missing studs become short cripples above the header instead.

How big should the header be?

That depends on the span, the load above (roof, floors, snow) and the lumber species and grade, and is set by the building code, not by this calculator. In the United States the International Residential Code has header span tables; your local building department can tell you which edition applies. The header stock figure here is only the length of lumber, two plies per opening.

Two or three studs at a corner?

A traditional corner uses three studs (two extra beyond the layout stud) and gives solid nailing inside and out. A two-stud corner with drywall clips, sometimes called a California corner, uses one extra stud and leaves room for insulation. Choose whichever your plans or local practice call for.

What is 19.2 inches on center?

A layout that puts five studs in every 8 feet (96 / 5 = 19.2), so sheet edges still land on framing. It is used with engineered floor joists and sometimes in advanced framing; check that your sheathing and drywall are rated for the wider span before using it for walls.