Stud Count Calculator: Studs & Plate Length

A stud wall is a row of vertical studs spaced a fixed distance apart on centre, capped by plates top and bottom. The count starts with the spacing: divide the wall length by the on-centre spacing — 16 in or 24 in are the usual choices — and add one, because a wall of n bays needs n + 1 studs to close both ends. A 20 ft wall at 16 in on centre is 15 bays, so 16 studs before anything else.

Real walls need more than the evenly spaced studs. Each corner takes extra studs to form a nailing surface for drywall, partitions that tee into the wall need a stud or a channel where they land, and every window and door adds a pair of king and jack studs plus cripples. Rather than guess, the tool lets you add a lump allowance for those corners and intersections on top of the on-centre count.

Plates are counted by length, not by the stud. A conventional wall has a single bottom plate and a doubled top plate — three plate lengths in all — so the plate stock is the wall length times three. Enter the wall length, pick the spacing, and set an allowance for corners and partitions; the tool returns the stud count and the plate linear feet. It does not add the king, jack, and cripple studs around specific openings — lay those out per opening.