Wall framing calculator

The formula, in plain words

1. 1Common studs per wall = length ÷ centres, rounded up, + 1. Timber is 450 mm, or 600 mm for internal non-loadbearing walls; steel up to 600 mm.
2. 2Timber extras: an external corner has three studs (each wall entered separately already ends in one, so a corner adds one), a T-junction a blocking stud, and each opening a jamb and a trimmer stud on either side. Steel: a stud at each corner and junction, and boxed studs beside each opening.
3. 3Plates = wall length × (1 bottom + 1 or 2 top). Steel track runs top and bottom in 3.0 m lengths.
4. 4Timber nogging rows = height ÷ 1.35 m, rounded up, − 1. Steel rows come from the maker's table: none to 4.4 m lined both sides, one to 3 m lined one side.
5. 5This counts members only; it doesn't size studs, lintels or bracing.

Worked example

A 6 × 2.4 m timber wall at 450 mm centres with one door opening and a single top plate.

1. 1.Common studs: 6 ÷ 0.45 = 13.3, so 14 spaces and 15 studs.
2. 2.The opening adds a jamb and a trimmer stud each side: 19 studs in all, plus one lintel.
3. 3.Plates: 6 × 2 = 12 m. Noggings: 2.4 ÷ 1.35 = 1.8, so 2 spaces and 1 row: 6 m.

Answer: 19 studs, 12 m of plate, 6 m of nogging and one lintel.

How to measure it

• Measure each wall's length and the floor-to-ceiling frame height.
• Count the external corners, T-junctions where walls meet, and the door and window openings.
• Check the stud centres on the frame drawings: 450 or 600 mm.
• Loadbearing walls, lintel sizes and bracing come from the frame design, not this count.

Where the numbers come from

Every default in the calculator is a number a supplier or manufacturer publishes. We list the source next to it so you can check.

Frequently asked questions