How to use the board and batten calculator
- Enter the wall width you are covering, wall to wall or corner to corner.
- Enter the batten height. Use the full wall height for floor-to-ceiling battens, or the height of your top rail for a wainscot-style wall (often 4 to 5 ft).
- Enter the batten width as its actual size: a 1×4 is 3.5 inches wide, a 1×3 is 2.5 inches.
- Enter a target gap. The calculator rounds to a whole number of equal gaps no wider than your target, so the first and last battens sit tight to the corners.
- Enter horizontal rails: a top rail, plus any mid rails for a grid look. Existing baseboard is not counted.
The spacing formula
Gaps = round up ((wall width − batten width) ÷ (target gap + batten width))
Battens = gaps + 1 · actual gap = (wall width − battens × batten width) ÷ gaps
Linear feet = battens × batten length + rails × wall width
Battens stop under the rails, so each batten is the batten height minus the rail widths. All widths are in inches; the calculator converts.
Worked example
A 12 ft (144 in) wall, battens 8 ft high, 1×4 battens (3.5 in), target gap 16 inches, one top rail, 10% waste:
- Gaps: (144 − 3.5) ÷ (16 + 3.5) = 7.2, rounded up to 8 gaps
- Battens: 8 + 1 = 9
- Actual gap: (144 − 9 × 3.5) ÷ 8 = 14.06 in (just over 14 1/16 in), or 17.56 in on center
- Batten length: 96 − 3.5 = 92.5 in (7 ft 8.5 in)
- Trim: 9 × 7.71 + 12 = 81.4 ft, with 10% = 89.5 linear feet, or 12 boards of 8 ft
Choosing batten size and spacing
- Gap of 12 to 24 inches covers most interior designs. Narrow gaps look busier and take more trim and painting time; wide gaps read as modern and minimal.
- 1×3 or 1×4 battens are the usual interior choice. Under PS 20 lumber sizing, a 1×4 is 3/4 × 3 1/2 in and a 1×3 is 3/4 × 2 1/2 in. MDF strips in the same widths are cheaper and paint smoothly.
- Exterior board and batten siding uses wide boards (often 1×10 or 1×12) with 1×2 or 1×3 battens over each joint; there, battens are spaced by the board width, and the boards themselves are counted with the linear feet calculator.
Do you need a backing panel?
On smooth drywall, battens can go straight on the wall. On textured walls, many people first install 1/4 inch hardboard or MDF panels so the gaps are flat; the calculator shows the wall area and the number of 4 × 8 sheets (32 sq ft each) for that option.
Installation tips
- Find the studs and mark them; nail battens with 18-gauge brads into studs where possible, plus construction adhesive.
- Lay out from the center of the wall if an outlet or window would land awkwardly, then adjust the gap slightly.
- Use a spacer block cut to the exact gap rather than measuring every board.
- Caulk and fill nail holes and seams before painting for a built-in look.
Frequently asked questions
How far apart should board and batten be?
Most interior board and batten walls use gaps of 12 to 24 inches between battens. Pick a target and divide the wall into equal gaps so the spacing is even edge to edge.
How many battens do I need for a 10 ft wall?
With 1×4 battens and a gap of about 16 inches, a 10 ft (120 in) wall needs 7 battens with six equal gaps of about 15.9 inches.
What size boards are used for board and batten?
Interior walls usually use 1×3 or 1×4 boards or MDF strips for battens and rails. Exterior siding uses wide 1×10 or 1×12 boards with 1×2 or 1×3 battens over the seams.
How do you calculate board and batten spacing?
Subtract one batten width from the wall width, divide by the target gap plus one batten width, and round up to get the number of gaps. Then divide the leftover wall space evenly among those gaps.
How much does a board and batten wall need in materials?
Add the length of all battens and rails, then add about 10% for cuts. A 12 ft wall with 9 battens 8 ft tall and one top rail needs about 90 linear feet.