About this calculator
Estimates the take-off for a light timber-frame stud wall: stud count from spacing plus jamb studs at openings, plate and noggin (blocking) length, OSB/plywood sheathing sheets, insulation packs, and vapour barrier rolls.
Formula
studs (excl. waste) = ceil(wall length / spacing) + 1 + extra studs per opening × opening count
studs (incl. waste) = ceil(studs × (1 + waste% / 100))
plate length = plate count × wall length
noggin length = noggin rows × wall length
net area = wall area − Σ opening areas
sheathing sheets = ceil(net area / (sheet width × sheet height)), then + waste%
insulation packs = ceil(net area (m²) / pack coverage (m²))
vapour barrier rolls = ceil(net area × (1 + overlap%) / roll area (m²))
Stud count is a simplified regular-spacing layout (bays + one end stud, plus jamb studs at each opening) — it does not model shared corner studs between adjoining walls or cripple studs above and below an opening. Noggin length per row is approximated as the full wall length, ignoring the small amount taken up by stud thickness at each bay.
Worked example
Defaults: 6 m × 2.5 m wall, one 900×2100 mm door opening, 600 mm stud spacing, 2 jamb studs per opening, 3 plates, 1 noggin row, 10% waste, 1200×2400 mm sheathing sheets, insulation at 5 m²/pack, vapour barrier with 10% overlap at 45 m²/roll.
studs = ceil(6000/600) + 1 + 2×1 = 10 + 1 + 2 = 13
studs incl. waste = ceil(13 × 1.10) = 15
plate length = 3 × 6 m = 18 m; noggin length = 1 × 6 m = 6 m
net area = 15,000,000 − 1,890,000 = 13,110,000 mm²
sheathing sheets = ceil(13,110,000 / 2,880,000) = 5, incl. waste ceil(5.5) = 6
insulation packs = ceil(13.11 / 5) = 3
vapour barrier = ceil(13.11 × 1.10 / 45) = 1 roll
FAQ
Does this calculator check whether the stud spacing is adequate for a load-bearing wall? No. Stud spacing and sizing for a load-bearing wall is a structural decision — an info diagnostic reminds you that framing design must be verified by an engineer. This calculator only counts quantities for the spacing and sizes you enter.
Why doesn't the calculator cite a standard?
No standard was found with sufficient confidence covering a generic stud-count or
sheathing/insulation take-off formula, so meta.standards is left empty.
Assumptions and limits
Stud count, noggin length, sheathing, insulation, and vapour barrier quantities are all simplified area/length-based estimates, not a real stud-by-stud framing plan. Insulation pack coverage and vapour barrier roll area are disclosed estimates you can adjust to match your own product. This is a quantity take-off only — framing design must be verified by a qualified engineer.