Slat Wall Panel Calculator
How many slat wall panels do you need? The usual area rule usually buys a panel too many, because it adds waste for cuts that a run of 600mm panels does not have. Enter each wall and get a real layout: panels side by side, the last one cut to width, leftovers shared between walls, and the adhesive counted. You get the panels to buy and a cutting plan panel by panel.
Last reviewed: 30 September 2026
Walls
Each wall is a flat run of panels. Enter the width you want to cover and the height. A wall up to 2400mm high takes full-length panels.
Panels
Panels are Cheshire Mouldings' 2400 × 600mm acoustic slat panel, sold singly, because the fitting rules come from its instructions. Leave the extra allowance at 0%: the cutting plan already reuses leftovers, and a spare panel is shown on its own line in the results.
How Many Slat Wall Panels Do I Need?
Usually one fewer than the area rule says. The usual answer is the wall area plus 10%, divided by the 1.44 m² one 2400 × 600mm panel covers. In the table below that buys a panel more than the wall needs in 7 of 8 common walls. A 3000mm wall at 2400mm high takes exactly 5 panels, but the rule says 6.
The 10% is meant for cutting waste, but panels go side by side and only the last one in a run is cut to width. That offcut often covers the next wall. So this calculator lays each wall out as a run of 600mm panels, and packs every cut piece from every wall into panels. For walls of 3700mm and 900mm at 2400mm high that comes to 8 panels, where the area rule says 9. Cutting each wall from its own panels only would take 9, which is shown as a second column in the table.
No percentage is added on top, because the plan already reuses leftovers. A spare panel is shown as its own line, like the architrave in the skirting calculator.
How the Layout Works
- 600mm panels, left to right. Cheshire Mouldings: the side where the slat projects past the backing goes on the left, and the open side, where the slat is set back, on the right, ready to accept the next panel.
- The last panel cut to width. Cheshire Mouldings: "it may be necessary to cut the last panel to correct width". If the mark falls on a slat, put masking tape on the cut line.
- Cut to the wall height. Panels are 2400mm long. A wall up to that height takes full-length panels cut to height.
- Start pieces and end pieces. A cut panel gives a right-hand piece that keeps the set-back edge, so it can start a run, and a left-hand piece that keeps the projecting edge, so it can finish one. That is our reading of how the edges fit.
- Leftovers shared between walls. The plan packs the pieces from every wall into panels, with at most one start piece and one end piece in each, and no end piece under 100mm (our choice).
What it does not do: it does not lay walls taller than the panel, cut-outs for sockets and switches, battens, or two courses from one panel on a low wall. Enter each flat wall separately.
The Panel, With Sources
The calculator uses Cheshire Mouldings' acoustic slat wall panel, because every fitting rule here comes from its instructions. Cheshire Mouldings Acoustic Slat Wall Panel, Light Oak (WPKT9), 2400 x 600mm, pack quantity 1 is sold singly at Travis Perkins, which lists it as 2400 × 600mm with a depth of 22mm (the instructions say 21mm, and the thickness does not change the count). Other makes of slat panel may join differently, so their offcuts may not share the same way.
Where the Rules Come From
The fitting rules are from Cheshire Mouldings' acoustic panel fitting instructions (a 2400 × 600 × 21mm panel covering about 1.44 m², which way round the panels go, cutting the last panel to width, masking tape on the cut line, one cartridge of adhesive for 3 panels). The way pieces are shared between walls, and the 100mm shortest end piece, are our own working. Follow the instructions in your pack where they differ.
Common Walls: Panels Needed
Generated from the calculator above. Every wall is 2400mm high on 2400 × 600mm panels. The "area + 10%" column is the usual rule of thumb for comparison.
| Wall | Panels in the Plan | Area + 10% | Area Rule Over By | If Each Wall Cut Alone | Adhesive Cartridges |
|---|---|---|---|---|---|
| One 1200mm wall | 2 | 3 | 1 | 2 | 1 |
| One 1800mm wall | 3 | 4 | 1 | 3 | 1 |
| One 2400mm wall | 4 | 5 | 1 | 4 | 2 |
| One 3000mm wall | 5 | 6 | 1 | 5 | 2 |
| One 3400mm wall | 6 | 7 | 1 | 6 | 2 |
| One 4200mm wall | 7 | 8 | 1 | 7 | 3 |
| Two walls, 3700 + 900mm | 8 | 9 | 1 | 9 | 3 |
| Two walls, 2500 + 1300mm | 7 | 7 | - | 8 | 3 |
Use the calculator for your own walls. A small change to a wall width can change the count by a panel.
Frequently Asked Questions
How many slat wall panels do I need?
Usually one fewer than the area rule says. The usual sum is the wall area plus 10%, divided by the 1.44 m² each panel covers, and in 7 of the 8 common walls below it buys a panel more than the wall needs. A 3000mm wall at 2400mm high takes exactly 5 panels side by side, but the rule says 6. The 10% is there for cutting waste, and a slat panel is cut along its length at the end of a run, so the offcut of one panel often covers the next wall. This calculator lays each wall as a run of 600mm panels with the last one cut to width, and shares leftovers between walls. For walls of 3700mm and 900mm it needs 8 panels, where the area rule says 9. Cutting each wall from its own panels only would take 9.
How do the panels fit together?
Cheshire Mouldings' fitting instructions say to work left to right, with the panel side where the slat projects past the backing on the left and the open side, where the slat is set back, on the right, ready to accept the next panel. So each panel's right edge takes the next panel's left edge. That is why a run of panels starts and ends the way it does in the calculator.
Can I cut a panel to width?
Yes. The same instructions say the last panel may need cutting to the correct width: measure to the wall at the top and bottom to check it is parallel, transfer the measurements to the panel, and cut. If the mark falls on a slat, put masking tape on the cut line first. Use a fine-tooth handsaw or a circular saw with a sharp blade. If slats come loose after cutting, secure them with 15mm screws through the felt from the back.
Can I use the offcut on another wall?
Often, yes. A panel has a projecting edge on the left and a set-back edge on the right, so a panel cut across gives a piece that can finish a run (the left-hand part) and a piece that can start one (the right-hand part). One cut panel can therefore finish one wall and start another. That is our reading of how the edges fit, not a supplier rule, and the cutting plan shows exactly which pieces come from each panel. For the walls above, 2 panels are shared this way.
How much adhesive do I need?
Cheshire Mouldings says one standard cartridge of fast grab adhesive should be enough to install 3 panels. For 8 panels that is 3 cartridges. The calculator uses the panels in the cutting plan. Screws or battens are another way to fix them, so follow the instructions with your panels.
What if my wall is taller than 2400mm?
The panels are 2400mm long, so a taller wall needs a horizontal join, which this calculator does not lay. It warns you if a wall is higher than the panel. A shorter wall is fine: each panel is cut to the height you enter, and the offcut from the top is not reused.
Why only one panel in the list?
Every fitting rule on this page comes from Cheshire Mouldings' instructions: which way round the panels go, cutting the last panel to width, and one cartridge of adhesive for 3 panels. So the list has only Cheshire Mouldings' own panel, sold singly by Travis Perkins, which hosts the same instructions. Other slat panels may join differently. B&Q's self-adhesive 9mm panels, for example, come with instructions that only say to make sure the slats line up, so we cannot tell whether the offcut from one wall can start the next.
What is the shortest piece I can fit?
No supplier gives a minimum. We use 100mm at each end of a wall, which is our own choice, so the last piece is not a thin sliver. If your wall would leave less than that, the calculator balances the two ends or uses one fewer whole panel.
Are these panels for wet areas?
Cheshire Mouldings says its panels are for internal use and are also suitable for kitchens and bathrooms as long as they do not come into direct contact with water, and recommends sealing the slats and slat ends with an interior wood varnish. It is not a waterproof wall panel. For a shower, see our shower panel calculator.