Board and Batten Calculator — boards, battens and linear feet
Boards and battens from the wall length and the lumber's dressed face — exterior with a gap, or interior at a spacing — with linear feet and board feet.
How many boards and battens a wall takes, from the wall length and the real face of the lumber — exterior siding with a gap and a batten over every joint, or an interior wainscot with battens at a spacing around a whole room.
| Pitch | — |
|---|---|
| Boards | — |
| Battens | — |
| Linear feet, with waste | — |
| Board feet | — |
| Cap and base rails | — |
| Wall area | — |
A 1x10 is 9¼ inches wide, and the count comes from that, not from the ten. Dressed dry lumber under 8 inches nominal is ½ inch narrower than its name. At 8 inches and over it is ¾ inch narrower. Those are the PS 20 sizes the lumber-board-feet page uses. Boards are set with a gap so they can move. The gap plus the face is the pitch, and the wall length divided by the pitch, rounded up, is the board count. A 1x10 with a half-inch gap pitches at 9¾ inches, so a 120-foot run of wall takes 148 boards. Cut the gap to zero and the count barely moves. Go to a 1x12 and it drops to 123.
Battens: one per joint, and one to close each run. Every gap gets a batten, so the batten count is the board count plus one per wall run. The corner takes the last one. On the interior the battens carry the pattern rather than the joints. They sit on a flat wall at a spacing, 12 to 24 inches on centre, plus one at each corner, with a cap rail on top and a base rail below, both running the room’s perimeter less the doors. That interior mode is the ‘whole room’ case. Enter the perimeter as the wall length and the wainscot height as the height.
Openings come off the area, not the count. Boards run over and under a window, so a window does not save a board. It saves the length of board that would have crossed it. The page counts boards by wall length and deducts openings from the area, a door at 21 ft² and a window at 15, the figures the siding and drywall pages use. That is what the wall-area row is built on. The count, the linear feet and the board feet are all for the full wall at the full height, because a board that crosses a window is still bought whole and cut on site. Buy by the count and the length; the area tells you what the paint will take.
Face width = nominal − ½" under 8" nominal, − ¾" at 8" and over (PS 20, American Softwood Lumber Standard, dressed dry sizes), which is what a surfaced board from a lumberyard measures. Rough-sawn and green boards run wider, and a milled pattern with a shiplap or a rabbet covers less than its face; measure a sample and adjust the gap to suit. Exterior: pitch = face + gap; boards = ceil(length ÷ pitch); battens = boards + wall runs. Interior: battens = ceil(length ÷ spacing) + wall runs; rails = 2 × (length − doors × 3 ft). Linear feet = count × height × (1 + waste). Board feet = nominal thickness × nominal width × those same linear feet ÷ 12, so the board-foot figure carries the waste allowance too. Openings at 21 ft² per door and 15 per window, and 3 ft per door width, are nominal figures. Measure yours. The half-inch gap and the 16-inch spacing are common starting points, not rules.
Worked example
A 120-foot run of wall, 9 feet high, in 1x10 boards with a half-inch gap and 1x3 battens: how many pieces?
- A 1x10 is 9¼" wide (PS 20); with a ½" gap the pitch is 9¾".
- 120 ft × 12 ÷ 9.75 = 147.7, so 148 boards; a batten per joint plus one per corner: 152.
- 148 × 9 = 1,332 ft of boards and 152 × 9 = 1,368 ft of battens; with 10%: 1,466 and 1,505 ft.
148 boards and 152 battens, about 1,470 and 1,510 linear feet. The count is by wall length; the door and windows come off the area, not the count.
23 values on this page were driven in a browser and compared with independently derived figures on 2026-09-06 (661 values across 69 calculators site-wide).
Questions
How many boards for board and batten siding?
Wall length ÷ (board face + gap), rounded up. A 1x10 is 9¼" wide; with a ½" gap it pitches at 9¾", so 120 ft of wall takes 148 boards and 152 battens — one per joint plus one per corner.
What size are board and batten boards?
Commonly 1x10 or 1x12 boards with 1x3 battens. Dressed lumber is ¾" thick and ¾" narrower than its name at 8" nominal and over (9¼", 11¼"), ½" narrower below it (a 1x3 is 2½") — PS 20.