How to use the wall panelling calculator
Panelled feature walls are back in a big way, from painted shiplap in living rooms to vertical tongue and groove in hallways, slatted timber behind beds and board and batten in dining rooms. Ordering is where projects go wrong: boards are sold by length, their exposed width is smaller than the nominal width, and battens need careful spacing. This calculator turns a wall size into the number of boards or battens to buy, plus adhesive and nails.
- Choose units and a style. Use Boards for shiplap, tongue and groove, beadboard, cladding-style panels or spaced slats. Use Board and batten for vertical battens with horizontal rails, including simple grid and picture-rail layouts.
- Enter the wall width and height. For a half-height or dado panel, enter the panelled height only.
- Deduct openings such as windows and doors for board layouts. Battens are counted across the full wall, because they usually stop either side of an opening rather than reducing in number.
- Enter the board details. For boards, use the exposed face width (cover width) and any gap, which is 0 for shiplap and T&G or 10–20 mm for slat walls. For battens, enter the batten width, a target spacing and the number of rails.
- Set the stock length, waste and fixing details. The adhesive and nail figures are estimates, so check them against the product data sheets.
Panelling formulas
Boards: rows = ⌈span ÷ (exposed width + gap)⌉, where span = height (horizontal) or width (vertical)
Linear length = rows × row length × (net area ÷ gross area)
Boards to buy = ⌈linear × (1 + waste) ÷ stock length⌉
Battens: verticals = ⌈(width − batten) ÷ spacing⌉ + 1 · rails = n × width · verticals between rails = height − n × batten width
Adhesive tubes = ⌈linear × beads ÷ bead length per tube⌉ · nails ≈ ⌈linear ÷ spacing⌉ × 2
Rows are rounded up, because the last board is ripped to fit. The opening deduction scales the linear length in proportion to the area removed, which is close enough for ordering. For battens, the tool rounds the count up and then spreads the battens evenly, so the actual spacing is equal to or slightly tighter than your target.
| Panel type | Typical exposed width | Notes |
|---|---|---|
| Shiplap (6 in nominal) | about 5–5½ in / 127–140 mm | Rebated overlap, often fixed horizontally |
| Tongue and groove | about 85–135 mm / 3½–5¼ in | Common for vertical and dado panelling |
| Slat wall | 30–60 mm slats with 10–20 mm gaps | Often on a dark backing or acoustic felt |
| Board and batten | battens 50–90 mm / 2–3½ in | Battens over a painted wall or sheet |
These widths are typical ranges, not standards. Always use the cover width of the product you are buying.
Worked examples
Horizontal shiplap in US units
A 12 × 8 ft living room wall gets shiplap with a 5½ in exposed face and no gap. The wall is 96 in high, so there are ⌈96 ÷ 5.5⌉ = 18 rows of 12 ft, or 216 linear feet. With 10% waste that is 237.6 ft, so 20 boards of 12 ft. At two beads per board and about 30 ft per tube, the adhesive needs ⌈216 × 2 ÷ 30⌉ = 15 tubes, and nailing every 16 in with two nails needs about 324 nails.
Vertical tongue and groove in a hallway
A 4.2 m long hallway gets 1.2 m high dado panelling in 95 mm cover T&G. The boards run vertically, so there are ⌈4,200 ÷ 95⌉ = 45 boards, each 1.2 m long, which is 54 m. With 10% waste that is 59.4 m. If the boards come in 2.4 m lengths, each cuts into two, so 25 lengths cover the run.
Board and batten in a dining room
A 3.6 × 2.4 m wall gets 70 mm battens at about 400 mm centres with a top and bottom rail. There are ⌈(3,600 − 70) ÷ 400⌉ + 1 = 10 verticals, actually spaced at 392 mm centres. Each vertical is 2.4 − 2 × 0.07 = 2.26 m, so the verticals total 22.6 m, and the rails add 7.2 m. That is 29.8 m, or 32.8 m with waste, which is 14 battens of 2.4 m.
Who this calculator helps
- Interior designers and architects specifying feature walls and checking joinery quantities.
- Carpenters and decorators pricing a panelling job and ordering boards in one trip.
- Home stagers and property developers adding a low-cost focal wall before photos or sale.
- DIY renovators planning shiplap, slat or board and batten walls for the first time.
Practical tips
- Acclimatise timber and MDF boards in the room for a couple of days before fixing, and leave a small expansion gap at the ends.
- Start horizontal boards from a level line, not the floor, because floors are rarely level. Plan the layout so you avoid a thin sliver at the ceiling.
- Work out the skirting and top trim with the baseboard and trim calculator, and the paint for the finished wall with the paint calculator.
- Comparing panelling with a patterned wall? The wallpaper calculator gives roll counts for the same wall.
- Paint or prime boards before fixing where possible. It is faster, and the joints will not show bare timber when the boards move.
Want to see the feature wall before buying the boards? Try colours and finishes on a photo of the room with AI Wall Paint.
