A stud wall is a timber-framed partition: vertical studs at regular centres, held between a top plate and a bottom (sole) plate. The stud count is the wall length divided by the spacing, rounded up, plus one to close the far end — studs = ⌈length ÷ spacing⌉ + 1. Two plates run the full length, so plate timber is twice the wall length, and the stud timber is the stud count times the wall height. Add it all up for a quick materials estimate, then allow extras for openings, noggins and waste.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: standard timber stud-partition framing practice.
The stud wall equations
Convert the spacing to the same unit as the length (or work in millimetres). Dividing length by spacing and rounding up gives the bays; adding one accounts for the closing end stud. The two horizontal plates each span the full wall, so they need twice the length in timber. Multiply the stud count by the wall height for the vertical timber, and sum the two for the rough total — before openings, noggins and a waste margin.
Worked example — a partition wall
Scenario: A partition 4.8 m long and 2.4 m high, with studs at 400 mm centres.
You need 13 studs and about 40.8 m of timber. Open the spacing to 600 mm centres and the studs drop to ⌈4800/600⌉+1 = 9, saving four studs and roughly 9.6 m of stud timber; tighten to 300 mm and it rises to 17. On top of this base, add two jack studs and a header per door, a row of noggins at mid-height, and about 10% extra timber for cutting waste when you place the order.
Frequently Asked Questions
studs = ⌈length ÷ spacing⌉ + 1. A 4.8 m wall at 400 mm centres = 13 studs.
400 mm (16") for stiffer walls and board edges; 600 mm (24") for less timber on light partitions.
The top (head) and bottom (sole) horizontal members. Plate timber = 2 × wall length.
Studs × height + 2 × length. 4.8 m × 2.4 m at 400 mm ≈ 40.8 m before openings, noggins, waste.
Usually — short horizontal blocking at mid-height to stiffen the wall and support board edges.