Stud Wall Spacing
Studs are spaced either 400 mm (16 in) or 600 mm (24 in) apart on centre. Here is how to choose between them - load, board thickness, fixings and cost - and how the spacing changes the number of studs you need.
By the Calculate My Reno Team / Published
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Stud spacing is the one decision that affects everything else on a partition - the number of studs, how solid the wall feels, and what you can fix to it. There are really only two answers: 400 mm (16 in) or 600 mm (24 in) on centre - that is, measured from the middle of one stud to the middle of the next.
Both are chosen so the long edge of a standard 1200 mm (4 ft) wide plasterboard sheet lands on the middle of a stud: 1200 ÷ 400 = 3 bays (the gaps between studs), 1200 ÷ 600 = 2 bays. That is why those two numbers, and not others, are the convention.
400 mm (16 in) vs 600 mm (24 in)
studs = floor(wall length ÷ spacing) + 1
(Here floor just means round down to a whole number, then add one for the stud that closes off the end of the wall.)
| 400 mm / 16 in | 600 mm / 24 in | |
|---|---|---|
| Timber used | More (extra studs) | Less |
| Wall stiffness | Higher | Adequate for partitions |
| Board support | Better - needed for thin or heavy finishes | Fine for 12.5 mm board |
| Typical use | Load-bearing, tiled or thin-board walls | Standard non-load-bearing partitions |
Use 400 mm (16 in) when the wall is load-bearing, when you will tile it (tile is heavy and unforgiving of any flex), or when you are boarding with thinner 9.5 mm sheet that would sag between wider studs.
Use 600 mm (24 in) for an ordinary partition clad in standard 12.5 mm (1/2 in) plasterboard. It is perfectly stiff enough, and the wider spacing saves a noticeable amount of timber on a long wall.
How spacing changes the count
Closer studs mean more timber. On a 4.8 m wall:
- At 600 mm: floor(4.8 ÷ 0.6) + 1 = 9 studs.
- At 400 mm: floor(4.8 ÷ 0.4) + 1 = 13 studs.
That is four extra studs - plus more noggins and more fixing - for the stiffer wall. Whether it is worth it comes down to load and finish, not preference. The stud wall calculator shows the count both ways as you switch the spacing, so you can see the timber difference instantly.
Don’t forget the noggins
Spacing sets the vertical studs; noggins (horizontal blocks, called blocking in North America) handle the rest - stiffening the wall across the studs and giving a fixing line for board edges and heavy fixtures. They are a separate decision from spacing; see noggins vs blocking. For the full build, read how to build a stud wall, and to price it, see what a stud wall costs.
Spacing for a load-bearing wall is governed by your local building code and the loads it carries - the guidance above is for non-structural partitions. Check the regional framing standard for anything structural.
Frequently asked questions
How far apart should studs be?
Studs are set either 400 mm (16 in) or 600 mm (24 in) apart, measured centre to centre. Use 400 mm where the wall is load-bearing, carries heavier finishes like tiling, or uses thinner board; 600 mm is fine for a standard non-load-bearing partition with 12.5 mm (1/2 in) plasterboard. Both space the studs so a 1200 mm (4 ft) wide board edge always lands on a stud.
Can studs be 600 mm (24 in) apart?
Yes, for a non-load-bearing partition boarded with standard 12.5 mm (1/2 in) plasterboard, 600 mm (24 in) centres are normal and use less timber. Go to 400 mm (16 in) if the wall is load-bearing, if you are tiling it, or if you are using thinner 9.5 mm board, which can sag or feel drummy at the wider spacing.
Why is stud spacing measured on centre?
Spacing is measured from the centre of one stud to the centre of the next ("on centre", or o.c.) so that the gap is consistent regardless of the timber width, and so that the edges of a standard 1200 mm (4 ft) board always fall on the middle of a stud. Measuring edge to edge would shift the board joints off the timber.
How many studs do I need?
Divide the wall length by the spacing and add one for the final end stud: studs = floor(wall length ÷ spacing) + 1. A 4.8 m wall at 600 mm centres needs floor(4.8 ÷ 0.6) + 1 = 9 studs; a 16 ft wall at 16 in centres needs 13. The stud wall calculator does this for you and adds the plates, noggins and board.