Wall Stud Calculator
Works out studs, plates, headers and noggins for a timber-framed wall. Openings add studs rather than saving them, which is the part rough estimates get backwards.
Includes corners, openings and waste.
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
The formula
common studs = floor(wall length ÷ spacing) + 1 extra = 2 per corner + 4 per opening + cripples plates = wall length × 3 (double top) or × 2
The "+1" closes the wall — a 6 m wall at 400 mm centres has 15 spaces and 16 studs. Openings add more than they remove: the king and jack studs either side are extra, and the studs they displace become cripples above the header and below the sill.
What to watch out for
What the count includes and why:
- Common studs at the spacing, plus one to close the end.
- Two extra per corner — the corner post needs backing for the plasterboard on both faces.
- Four per opening — a king stud full height and a jack stud under the header on each side — plus cripples over and under.
- Double top plate on anything load-bearing, lapped at the corners so the walls tie together.
The header section — whether it is a doubled 2 × 6 or a 2 × 10 — depends on the span and the load from above and comes from a span table or an engineer. This page gives the length to buy only.
Frequently Asked Questions
How many studs do I need for a wall?
Divide the length by the spacing and add one, then add two per corner and four per opening. A 6 m wall at 400 mm centres with two corners and one door is 16 + 4 + 6, about 29 with waste.
Should studs be 400 or 600 mm apart?
400 mm (16 in) is standard for load-bearing walls and for plasterboard that is 12.5 mm thick. 600 mm (24 in) is common on non-load-bearing partitions and saves about a third of the studs, but needs thicker board or it bows between them.
Do doors and windows reduce the stud count?
No — they increase it. Each opening needs a king stud and a jack stud on both sides, which are additional to the common studs, and the studs the opening displaces are cut into cripples above and below.