Board and Batten Calculator
Boards and battens for a wall of vertical board and batten siding, from the wall, board width, gap and openings.
Result
Buy 23 boardsEstimate
Whole runs cut from each stock board, rounded upNo extra is added by default. A run is never spliced when a stock board is long enough for it.
- Battens to buy
- 22Estimate
- Boards across the wall
- 23
- Battens across the wall
- 22
- Board length after openings
- 184 ft
- Batten length after openings
- 176 ft
- Width of the last board
- 9 in
- Batten lap onto each board
- 1 in
https://calcgallery.com/lumber-carpentry/board-and-batten-calculator/
Results are estimates for planning only. Actual needs vary with site conditions, products and workmanship. Always confirm quantities with your supplier and follow local building codes and manufacturer instructions. Read the full disclaimer
How to use the Board and Batten Calculator
- Enter the width and height of the wall, and the area of any windows and doors.
- Enter the actual face width of a board, the gap you leave between boards, and the batten width.
- Enter the stock length you will buy boards and battens in.
- Read the boards and battens to buy, how many sit across the wall, and how wide the last board is ripped.
How it is calculated
pitch = board width + gapboards across = ⌈(wall width + gap) ÷ pitch⌉battens across = boards across − 1last board = wall width − (boards across − 1) × pitchruns removed = openings ÷ (pitch × wall height)The wall width plus one gap is used because a row of boards has one fewer gap than boards. Pieces to buy are then counted by whole runs: a stock board as long as the wall gives one run, twice as long gives two. On a wall taller than the stock, where every run needs a joint, the count is by length and offcuts go into the joints. When the wall width ends exactly in a gap, no board of zero width is counted: the last full board stops a gap short of the edge. Windows and doors as large as the wall are refused, since there is nothing left to cover.
Before you cut
Board and batten is vertical siding, so the layout is about the ends of the wall. Starting with a full board at one corner leaves whatever the arithmetic gives at the other; the last board width shows it. If that sliver is narrow, splitting the difference between both ends usually looks better. Corner boards, trim, flashing and the drainage gap behind the siding are separate, and the manufacturer’s and local code requirements for exterior cladding vary and must be checked.
With your numbers
- Board plus gap = 10.5 in
- Boards across = ⌈(wall width + gap) ÷ 10.5 in⌉ = 23, with 22 battens over the gaps
- Boards to buy = 23, battens to buy = 22
Quick reference
No extra is added by default. A run is never spliced when a stock board is long enough for it.
| Job | Boards to buy |
|---|---|
| 20 × 8 ft wall, 10 in boards | 23 |
| 20 × 8 ft wall, 30 ft² openings | 19 |
| 20 × 8 ft wall, 16 ft stock | 12 |
| 12 × 9 ft wall, 7 1/4 in boards | 19 |
| 20 × 10 ft wall, 8 ft stock | 29 |
| 6 × 2.4 m wall | 23 |
Common questions about the Board and Batten Calculator
- How many boards and battens do I need for a 20 foot wall?
- With 10 inch boards and a half-inch gap, each board and its gap take 10.5 inches, so 23 boards cover 20 feet and the last one is ripped to 9 inches. There are 22 gaps, so 22 battens.
- How wide should the gap and the batten be?
- The page takes both from you. The batten has to be wider than the gap so that it laps onto both boards, and the page shows how much it laps onto each. It refuses a batten that does not cover the gap.
- Why does the board count not change when I use 10 foot stock on an 8 foot wall?
- A 10 foot board gives one 8 foot run and a 2 foot offcut, and board and batten runs are not spliced from offcuts because the joint shows. Stock twice the wall height gives two runs a board. When the wall is taller than the stock, runs are joined anyway, and the count goes by total length.
- How are windows and doors taken off?
- Their area is divided by the board-plus-gap width and the wall height, which gives the number of full-height runs they replace. That is exact for a door-height opening and close for a window, where short pieces above and below still have to be cut. Add an allowance if you have many small openings.