A 40 × 28 ft one-story house framed with 2x6 studs at 16 in on center, with ten 3 × 4 ft windows, two doors and 80 feet of interior partitions, takes about 225 studs: 106 full-height studs in the exterior walls, 8 at the corners, 77 in the partitions and 34 cut into jacks and cripples. Add 41 plates of 16 ft, 78 ft of two-ply header, 33 sheets of wall sheathing and about 1,100 framing nails. The calculator above works out the whole list for one or two stories, wall by wall.
How the calculator works
Enter the house length and width, the number of stories and the wall height, the windows on each wall and the exterior doors, then the stud size and spacing, the partitions and the header size. The result counts studs, plates, headers, floor joists, sheathing, inside walls, insulation, house wrap and nails, and estimates the dead weight on the foundation. The elevations show where the studs, openings and headers land.
Studs per wall
Each wall gets a stud at every spacing plus one at the end: a 40 ft wall at 16 in has ⌈480 ÷ 16⌉ + 1 = 31 layout studs. Studs that would fall inside a window or door are left out; a 36 in opening drops two. In their place each opening gets two full-height king studs, two jack studs that carry the header, and short cripples on the layout above the header and under a window sill. Jacks and cripples are cut from full studs, two pieces to a stud.
Corners, partitions and plates
A three-stud corner adds two studs at each of the four corners; each place a partition meets another wall adds two more for backing. Every wall sits on one bottom plate and carries a double top plate (IRC R602.3.2), so the plates are three times the length of all walls: 3 × (136 + 80) = 648 ft.
Headers
A header spans each opening and bears 1½ in on the jack stud at each end; built from two plies, a 36 in window needs two pieces 39 in long. The depth depends on the span, the floors and roof above, and the snow load: take it from IRC Table R602.7(1). The calculator counts the length in the size you choose.
Floors, skin and insulation
If the first floor sits on joists over a crawlspace or basement, and for every floor above, joists run across the width at the stud spacing. The calculator picks the smallest Douglas fir-larch No. 2 size for 40 psf live and 10 psf dead load at L/360: a 28 ft width spans no single size, so it adds a beam line and frames each 14 ft bay with 2x10s. Sheathing and drywall come in 4 × 8 sheets with 10 % for cuts, house wrap and poly in rolls with 10 % for laps, insulation in bags by the coverage printed on the label.
Weight on the foundation
Lumber, panels, insulation and the roof at the dead load you enter add up to the dead weight of the house; divided by the perimeter, it is a starting line load for the footing — about 200 lb/ft for the example, before floor live loads and snow.
Common mistakes
- One stud per foot. A quick rule that misses corners, partitions and openings — it is often 15–20 % short.
- Single top plate. Bearing walls need a double top plate with staggered splices.
- Header size by habit. A doubled 2x10 is not right for every opening; check the table.
For joist sizes, use the Joist Span Calculator; for the sheathing alone, the Plywood and Sheathing Calculator; for the footing under the walls, the Footing Calculator.