Free wall framing calculator. Studs, plates, dwangs, and nogs to B1 (Structure) spacing.
This calculator counts the lineal metres of timber in a stud wall — studs, plates, dwangs — plus the fixings to put it together. Give it the wall length, the stud height, the stud spacing and any openings.
Openings are taken out of the wall length first, then studs are the remaining length divided by the spacing, rounded up, plus one. Two trimmers are added per opening.
Stud spacing options are 400mm and 600mm centres. The bottom plate runs the full wall length including under the openings, because that is how a wall gets set out. The top plate is counted twice, for a double top plate.
A 12% wastage allowance is applied to the total lineal metres, not to each member separately.
Dwang rows are worked out to keep every unsupported stud span at 800mm or less. That count is the height divided by 0.8, rounded up, less one — because the top and bottom plates already close the outermost gaps. A 2.4m stud needs rows at 800 and 1600: two, not three.
The old formula rounded the other way and returned one row too many at every whole multiple of 800mm — 1.6m, 2.4m and 3.2m. Since 2.4m is both this field's default and the standard stud height here, the most common case on the page was roughly 10% over on the whole wall. Fixed 2 September 2026.
Each dwang is cut to the stud spacing less 45mm, for the width of the stud beside it.
Member sizes, lintels and bracing are design decisions. Check them against your plans and NZ Building Code B1 (Structure) before you order or build.