Slat Wall Calculator

Work out the slat count, exact gap, and material for a wood slat wall. Choose the gap you want and the calculator finds how many slats fit your wall evenly, or fix the count and get the gap. It also estimates how many MDF sheets to rip your slats from.

Slat wall spacing
Slats and exact gap60 × 13.2 mm

60 slats create 59 equal gaps of 13.2 mm. Cut a spacer block at that size and register every slat against it.

Slat length to buy (incl. 10% waste)158.4 m
Ripping your own from 2440 x 1220mm sheets2 sheets
One sheet rips into 40 full-height slats at this width.
Open this wall in the free planner

How slat spacing is worked out

The quick version: with a slat at each end of the wall, add one gap to the wall width and divide by the slat width plus the gap. Round to the nearest whole slat, then recalculate the exact gap from that whole count, because the rounding shifts the true gap slightly.

For example, a 2400mm wall with 27mm slats and a 13mm target gap: 27 + 13 is a 40mm repeat, and (2400 + 13) / 40 = 60.3, so 60 slats. The exact gap becomes (2400 − 60 × 27) / 59 = 13.2mm. That last recalculation matters on a slat wall: an error of half a millimetre repeated 59 times is a visibly crooked final slat.

When it comes to fixing, do not measure each position from the tape. Cut a spacer block at the exact gap width from scrap and register every slat against it, checking for plumb every five or six slats. Errors against a spacer do not accumulate.

What spacing looks right

Slat walls live or die on density. Ready-made acoustic panels set the reference look: 27mm slats with 13mm gaps, where the wall reads as a single fluted surface. Keeping the gap at or below the slat width holds that dense, corduroy-like texture. Opening the gap up to one or two slat widths, like the 20mm slats with 45mm gaps in our slat wall template, reads lighter and more graphic.

Whatever spacing you choose, paint the wall behind a dark colour first. The gaps are shadow lines, and they only read as deep flutes against a dark backing.

Common wall widths

A quick reference for the acoustic-panel look: 27mm slats aiming for a 13mm gap, one slat at each end. Your slat width changes these numbers, so use the calculator for your exact wall.

Wall widthSlatsExact gap
1800mm4513.3mm
2400mm6013.2mm
3000mm7513.2mm
3600mm9013.1mm

How much material a slat wall needs

The calculator totals the linear length of slat on the wall, adds a 10% waste allowance for offcuts and miscuts, and shows the result two ways: as strip length to buy, and as the number of standard 2440 x 1220mm sheets to rip your own slats from. The sheet count allows a 3mm saw kerf per cut, which is the detail most people forget and the reason a sheet yields one or two fewer strips than the simple division suggests.

Walls taller than a sheet is long need full-length strips or planed timber instead, since joins mid-slat are hard to hide on a wall you read at eye level. For pricing either route, our wall panelling cost guide has current per-sheet and per-strip figures.

Plan the whole wall

Spacing is the first step. The free planner draws your slat wall to scale, lets you drag the count and spacing until it looks right, handles sockets and radiators, and produces a cut list of every strip to take to the timber merchant. Open your numbers straight from the calculator above, or start from the slat wall template.

Open the planner

Slats, battens, or panels?

A slat wall is board and batten at high density: same geometry, narrower strips, tighter gaps. If your design uses wider battens spaced further apart, the batten spacing calculator starts from the batten count instead. For framed boxes running the full height, like shaker, use the wall panel spacing calculator, and for framed panels that stop at a chair rail, the wainscoting calculator sizes the lower band and the rail height together.

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Frequently asked questions

What is the best gap between slats on a slat wall?

Most slat walls use a gap between half the slat width and roughly the slat width itself. Ready-made acoustic panels run 27mm slats with 13mm gaps, which is the dense fluted look. Wider gaps, like 20mm slats with 45mm gaps, read lighter and more open. Enter your slat width and try a few gaps in the calculator until the preview looks right.

How many slats do I need for my wall?

Add one gap to the wall width, then divide by the slat width plus the gap, and round to the nearest whole number. That is the count with a slat at each end. The calculator does this for you, then recalculates the exact gap from the whole count, since the rounded count shifts the true gap slightly.

Is it cheaper to rip my own slats or buy acoustic panels?

Ripping your own slats from MDF sheets usually costs a quarter to a third of ready-made acoustic panels, but you supply the labour: cutting, priming, and fixing every strip. Bought panels win when you want a real wood veneer finish, which is hard to match with stain. The calculator shows how many sheets your wall needs so you can price both routes.

What colour should the wall behind the slats be?

Dark. The gaps between slats read as shadow lines, and shadow against a white wall looks grey and flat. Paint the wall behind in an off-black or the deepest tone of your slat colour before fixing anything. This is why commercial acoustic panels all use black or anthracite felt backing.

Do slats have to run vertically?

Vertical is the classic slat wall and adds height to a room. Horizontal works too and makes a room feel wider. The maths is the same turned on its side: enter your wall height as the width and the calculator spaces the slats across it.

Related guides

Slat wall panelling: the full style guideHow much does wall panelling cost?