Stud Calculator

Sixteen inches divides evenly into the 48-inch width of drywall, plywood, and OSB, so every panel edge lands on a stud with two studs supporting the field in between — no cutting to fit, no floating seams. It also matches the span ratings printed on sheet goods and leaves walls stiff enough for cabinets, tile backer, and heavy trim. Layout starts at 15¼ inches from the end of the wall so the first sheet breaks on the center of the fourth stud. It remains the default for exterior walls and load-bearing interior walls in most of the country.

The IRC allows 24-inch spacing for many walls — 2×6 exterior walls in one- and two-story houses and most non-load-bearing partitions are the common cases — and "advanced framing" uses it deliberately to cut lumber and open up cavity for insulation. The trade-offs are real: drywall thinner than ⅝ inch can telegraph between studs, and sheathing and siding must be rated for the wider span. Whether your specific wall qualifies depends on its load, height, and local amendments. Treat this as a planning estimate and let your building department or a licensed pro confirm the spacing.

A king stud runs full height from plate to plate alongside an opening. A jack (or trimmer) stud is nailed to the king, stops under the header, and carries the header load down to the bottom plate. Cripple studs are the short pieces that fill above a header or below a window sill, kept on the same layout as the commons so sheathing and drywall still find backing. A standard opening gets two kings and two jacks; because those replace commons that fell inside the opening, this calculator adds two studs net per opening.

A traditional corner post uses three studs: two forming the outside corner and a third turned inward as a nailer, so drywall on the intersecting wall has something to fasten to. Framers usually build the post as a unit before standing the wall. Three-stud corners leave almost no room for insulation, which is why California corners — two studs plus drywall clips — are common in cold climates. This calculator adds three studs for one corner or wall intersection; add three more for every additional corner your run turns.

Platform framing uses one bottom plate and a doubled top plate, so plate lumber equals three times the wall length — 60 linear feet for a 20-foot wall, or eight 8-foot boards. Buy plate stock in the longest lengths you can handle and stagger the joints in the two top plates by at least 24 inches, as the IRC requires; most framers push that to 4 feet. The double top plate is what ties intersecting walls together and carries joists or rafters that do not land directly over a stud.

No. The count covers common studs, a three-stud corner, the net extras at openings, and plate stock. You still need headers sized for the span and load above each opening, fire blocking where code calls for it, sheathing, nails, and any hold-downs or straps on the plan. Header sizing in particular is structural — it depends on span, roof and floor loads, and snow load — so use a span table from your code book or have it specified by an engineer. This tool is a material estimate, not an engineered design.