About the Board and Batten Calculator
This board and batten calculator handles the two jobs people mean by "board and batten". For an interior accent wall, it takes the wall width and your target spacing and works out how many vertical battens you need and the exact, even gap between them so the first and last battens sit tight to the corners. For exterior or barn-style siding, it counts the wide boards and the battens that cover each joint.
It is meant for DIYers planning a feature wall in a living room, nursery or entryway, and for anyone pricing vertical siding on a shed, garage or house. Enter actual (dressed) lumber sizes — a 1×3 is about 2.5 inches wide and a 1×10 about 9.25 inches.
Stock sticks are counted piece by piece, so short battens on a half-height wall are cut two or more from one board. The layout assumes one continuous wall; for walls broken by windows, run the calculator per section.
With the default inputs, the vertical battens is 10. Change any value above to recalculate instantly.
How to use the board and batten calculator
- 1Choose an accent wall or siding layout.
- 2Measure the wall width corner to corner and the height the battens will cover.
- 3Enter actual lumber widths, not nominal sizes.
- 4Set a target spacing (wall) or board width and gap (siding).
- 5Mark the centers using the adjusted spacing and buy the stock pieces shown.
Formula and method
For an accent wall the first and last battens sit at the corners, so the distance from the center of the first to the center of the last batten is the wall width minus one batten width. Dividing that by your target spacing and rounding gives the number of equal spaces k; the battens are k + 1 and the real spacing is recalculated so every gap is identical. Vertical battens are shortened by the width of any horizontal rails.
For siding, each board plus one gap takes up B + g inches, so the board count is the wall width plus one gap divided by B + g, rounded up, and one batten covers each joint between boards. Stock pieces are counted per piece: battens shorter than a board are cut several from one stick.
- W
- Wall width (in)
- b
- Batten width (in)
- s
- Target center-to-center spacing (in)
- B, g
- Siding board width and gap between boards (in)
Worked examples
12 ft accent wall, 1×3 battens at about 16 in, top rail
(144 − 2.5) ÷ 16 = 8.84, which rounds to 9 equal spaces, so 10 battens at 15.72 in centers (13.22 in gaps). Each vertical is 96 − 2.5 = 93.5 in long, one per 8 ft stick, plus two sticks for the 12 ft top rail: 12 pieces.
10 ft half-height wall, 1×4 battens at 12 in, top and bottom rails
(120 − 3.5) ÷ 12 = 9.7 → 10 spaces, 11 battens at 11.65 in centers. Each vertical is 48 − 7 = 41 in, so two come from each 8 ft stick (6 sticks), plus 2 sticks for each 10 ft rail: 10 pieces.
24 ft wide, 10 ft tall siding with 1×10 boards and 1×3 battens
Each board plus its 1/2-inch gap takes 9.75 in, and (288 + 0.5) ÷ 9.75 = 29.6, so 30 boards with 29 battens over the joints — each one a full 10 ft stick.
Frequently asked questions
How far apart should board and batten be spaced?+
Interior accent walls usually use 12 to 24 inches center to center; 16 inches is popular because it often lands on studs. Narrow walls look better with tighter spacing, and the calculator adjusts your target so every gap is equal.
What size boards are used for board and batten?+
Accent walls commonly use 1×3 or 1×4 boards (or MDF strips) about 2.5–3.5 inches wide. Exterior siding typically uses 1×8 to 1×12 boards with 1×2 or 1×3 battens covering the joints.
Do battens go on studs?+
Nail into studs where you can, but battens on an interior wall are light and are commonly fixed with construction adhesive and brad nails into drywall where a stud is not available. Exterior siding must be fastened to framing or blocking.
Should I start with a batten in the corner?+
Yes — most layouts put a batten tight to each corner so the wall looks framed. That is why the number of battens is one more than the number of spaces.
How much gap should siding boards have?+
A gap of about 1/2 inch between boards is common to allow for wood movement, with battens wide enough to overlap each board by at least 3/4 inch on both sides.