Stud Calculator

16 inches on center (OC) is the most common spacing for residential walls in North America. It accommodates standard 4×8 sheathing and drywall without mid-span seams. 24" OC (advanced framing) uses fewer studs and more insulation — code-compliant for many single-story applications but requires engineering review for load-bearing walls. 12" OC is used for tall walls, heavy loads, or seismic zones.

King studs run full height from bottom plate to top plate on each side of an opening. Jack studs (also called trimmer studs) sit inside the king studs and support the header over the opening — they are shorter, cut to header height. Cripple studs fill the space between the header and the top plate, maintaining the OC spacing across the opening. All three types are counted in the Opening Framing output.

The standard 3-stud corner uses two studs forming an L-shape at the corner, with a third stud providing a nailing surface for interior drywall. This adds 4 extra studs per wall (2 at each end). An alternative California corner uses only 2 studs with drywall clips — it saves one stud per corner and improves insulation continuity, but requires clips and a slightly different drywall installation sequence.

Yes — load-bearing walls require doubled top plates to transfer load across stud-to-stud gaps and create a continuous structural tie. The double plate is not included in the stud count but requires one additional run of lumber the full wall length. Non-load-bearing partition walls may use a single top plate in some jurisdictions — verify with your local building code.

Add 10% for straightforward rectangular walls. Increase to 15% for walls with many corners, angled sections, or complex header situations. Miscuts, split lumber, and last-minute adjustments are common — running short of studs mid-frame is a project delay. Leftover studs are easily used elsewhere or returned to most lumber yards.

For 9-foot finished ceiling height, use 104-5/8 inch precut studs (standard 9-ft stud). With a double top plate (3 inches) and single bottom plate (1.5 inches), the total wall assembly is 9 ft exactly. For 8-foot ceilings, use 92-5/8 inch studs. Precut studs are sold in these lengths at most lumber yards and eliminate the need to cut each stud to length.

Run this calculator once per wall, then add the totals. Shared corners between intersecting walls may let you reduce the count slightly — one wall's end studs can serve as the corner assembly for the adjacent wall. In practice, most framers calculate each wall independently and add 10% overall, since lumber is inexpensive relative to labour and a separate trip for a few extra studs costs far more than the boards themselves.