Wall panelling calculator
Work out even spacing for shaker (box) panelling or vertical battens. Get the exact gap, where to mark each strip from the left, every cut length, a scaled diagram of your wall and how many lengths of MDF or timber to buy.
Measure from the floor, not the top of the skirting. Use 0 for no skirting. Common MDF strip widths are 44, 69, 94 and 119 mm.
Boxes
Battens
Sockets and switches (optional)
Add any socket, switch or vent on the panelled part of the wall to get a warning if a strip lands on it. Measure to its left edge from the left of the wall, and to its bottom edge from the floor. A UK single socket or switch plate is 86 × 86 mm.
Buying and cutting
Separate lengths with commas, like 2400, 2700.
Updates as you type. Runs in your browser. Nothing you enter is stored or sent.
Your wall
Drawn to scale. Strips are numbered from the left. Dimensions are in mm.
Where to mark each strip
| Strip | Left edge | Right edge |
|---|
Where to fix the rails
Heights from the floor.
| Rail | Bottom edge | Top edge |
|---|
Pieces to cut
| Piece | Qty | Length |
|---|
What to buy
| Length | Needed | Buy | Total |
|---|
How this calculator works
Even spacing is just the wall width minus the strips, shared between the gaps. What changes is how many gaps there are.
Shaker boxes: there's a vertical strip (a stile) at each end and between every box, so n boxes need n + 1 stiles. Box width = (wall width − (n + 1) × strip width) ÷ n.
Battens, starting with a batten: n battens leave n − 1 gaps. Gap = (wall width − n × batten width) ÷ (n − 1).
Battens, starting with a gap: n battens leave n + 1 gaps. Gap = (wall width − n × batten width) ÷ (n + 1).
For example, five boxes across a 3,600 mm wall with 69 mm strips need six stiles taking up 414 mm, which leaves 3,186 mm for five boxes of 637.2 mm each.
If you give a target box width or gap instead of a number, the calculator picks the whole number of boxes or battens that gets closest to it, then works out the exact even spacing. It also shows the options either side, so you can choose a layout you like.
The box height is the height to the top of the panelling, minus the skirting, minus the rails, divided by the number of rows. The rails (horizontal strips) run the full width of the wall, and the stiles fit between them.
Marking positions are all measured from the left-hand end of the wall, so small rounding doesn't build up as you go along the wall the way it would if you measured each gap from the last strip.
The cutting list adds the saw kerf to every cut, then packs the pieces into the lengths you can buy, longest piece first, putting each one in the first length with room (first-fit decreasing). It's quick and usually close to the fewest lengths, though not always perfect. Rails longer than the lengths you can buy are split so the join sits on the centre line of a stile, where it lines up with the panelling and is easier to hide. The spare percentage is added on top and rounded up to whole lengths.
Tips for panelling a wall
- Measure in several places. Walls are rarely square. Measure the width at the top, middle and bottom, and the height at each end, and use the smallest figure. Check the corners too, because a strip at the end may need scribing to fit.
- Mark with a level, not a tape from the floor. Floors and ceilings are often out of level, so use a laser level or a long spirit level to draw your rail lines, and plumb each stile or batten with a level as you fix it.
- Cut a spacer block. Cut a scrap of wood to the exact gap or box width and use it between strips. It's quicker than measuring each time and keeps the spacing even.
- Fix it well. Use a panel adhesive like No More Nails or a grab adhesive on the back, with panel pins or a nail gun to hold the strips while it sets.
- Finish before you paint. Fill nail holes, caulk the joins and the edges where strips meet the wall, sand lightly once dry, then prime MDF before painting. Caulk hides a lot of small gaps.
- Check behind the wall. Use a detector to check for cables and pipes before nailing or screwing. Cables often run straight up, down or across from sockets and switches.
- Plan around sockets and switches. If a strip lands on a socket, try one box or batten more or fewer. You can also cut a strip around a faceplate, or have an electrician fit a socket extension box so the faceplate sits on the panelling.
Safety: always check walls for hidden cables and pipes before drilling, nailing or screwing, and switch off the power at the consumer unit before working around sockets or switches. Measurements are a guide. Check them on your wall before you cut.
Frequently asked questions
How do I space shaker panelling evenly?
Decide how many boxes you want across the wall, then take away one strip width for every stile (one more than the number of boxes) and divide what's left by the number of boxes. That's your box width. This calculator does that for you and gives the marking position of every stile from the left.
How wide should shaker panel boxes be?
There's no fixed rule, but boxes roughly 400 to 700 mm wide look balanced on most walls, and many people like boxes a little taller than they are wide. Try a few numbers of boxes and look at the diagram to see which you prefer.
What size MDF strips should I use?
69 mm and 94 mm MDF strips are the most popular for shaker panelling, usually 6 mm to 12 mm thick. Wider strips suit bigger walls and taller boxes. For vertical slats, narrower strips like 34 mm or 44 mm are common.
How high should half-wall panelling be?
A common choice is about one third to just under half the wall height, which is around 900 to 1,200 mm in most UK rooms with 2.4 m ceilings. Line it up with things like window sills where you can.
Should battens start with a batten or a gap at each end?
Starting with a batten at each end gives the wall a framed, finished edge and is the most common choice. Starting with a gap suits walls that meet a door frame or another panelled wall, where a batten right in the corner would look crowded.
What if the battens don't divide evenly into my wall?
They nearly always divide evenly, because the calculator changes the gap, not the batten width. If your target gap was 100 mm, it might come out as 98.6 mm. If a gap feels too far from what you wanted, try the other number of battens shown under the results.
What is saw kerf?
Kerf is the width of material the saw blade turns into dust with each cut, usually about 2 to 3 mm for a mitre saw or circular saw. If you ignore it, several pieces cut from one length come out short.
Does it save my measurements?
No. Everything is calculated in your browser and nothing is stored or sent anywhere. Use the copy button to keep a note of your measurements.