Sixteen inches on center, everywhere
Residential walls frame studs at 16 inches on center so standard 4×8 sheathing and drywall land on stud edges; 24-inch spacing is allowed for some siding and economy builds. The calculator converts wall length to stud count — every opening adds studs for the jack and king layers on each side.
Corners and openings eat studs
A corner needs three studs (two walls' worth), and every door or window adds two jack studs, two king studs and cripples above. A 40-foot wall with two windows and a door runs roughly 60% more studs than the bare-spacing math — the calculator gives the baseline, count the openings on top.
Sources and standards
Where these figures come from
Every formula on this page is implemented from the published reference material below. Where a value depends on a regional code, the calculator lets you override it rather than assuming one jurisdiction.
- American Wood Council — span tables, lumber design values and the Wood Frame Construction Manual.
- APA — The Engineered Wood Association — panel span ratings and sheathing installation guidance.
Figures, formulas and reference tables last verified: 19 September 2026.