Stud Wall Calculator
Work out how many studs you need for a wall, based on wall length, wall height and center spacing (on-center) — or the other way around: how long a wall a given number of studs will cover.
How to use the stud wall calculator
- Enter the length and height of the wall you're building.
- Enter the desired center spacing in millimeters — 600 mm is standard for most interior walls.
- The calculator shows the number of studs, plus how many running meters of stud timber and plate you need.
How the number of studs is calculated
The calculator divides the wall length by the center spacing, rounds up, and adds one extra stud at each end:
Meters of stud timber is found by multiplying the number of studs by the wall height. Meters of plate is calculated as twice the wall length, since both the top and bottom plate run along the entire wall.
The "How long a wall can I cover?" tab flips the calculation around: you enter how many studs you have on hand, and the calculator works out the longest wall they'll cover at a given spacing.
Stud spacing is set by what goes on the wall
Stud spacing is not a free choice — it follows the board width of whatever is fixed to the outside. Standard board formats are made to land on the studs at the usual spacing, so that every board joint falls on the centre of a stud and is supported on both sides. Choose a different spacing and boards have to be cut to land correctly, giving both more offcuts and more joints without full support.
Closer stud spacing is used where the wall carries more load or where the cladding demands it — for heavy tiling in a wet room, for instance, or for tall walls. Around windows and doors there will in any case be extra studs and headers on top of the regular spacing, and those are not included in a plain length calculation.
Frequently asked questions
What's a common center spacing for stud walls?
600 mm (16" is the closest imperial equivalent) is most common for interior walls in homes, and works well with standard panel widths like 1200 mm. Load-bearing walls can have 400 or 600 mm spacing depending on structural requirements.
Do I need extra studs around doors and windows?
Yes, openings for doors and windows require extra studs and often a header to stiffen the structure. This must be added on top of the calculated number in this calculator.
What's the difference between a stud wall and a timber-framed wall?
Both terms describe essentially the same build-up, with vertical studs between a top and bottom plate. "Timber frame" is often used for load-bearing exterior walls, while "stud wall" is often used for non-load-bearing interior walls.
I have a set number of studs on hand — how long a wall will they cover?
Use the "How long a wall can I cover?" tab. Enter the number of studs and your desired center spacing — the calculator works out the longest wall they'll cover. Useful for using up leftover material or planning a purchase.