How to use the board and batten calculator
- Enter the wall width and wall height in feet. The height is the length of each batten.
- Enter the batten width and the spacing, measured center to center. The spacing is the most you want between batten centers.
- Choose whether to put a batten at both wall ends or only between them, and the length of the boards you will buy.
- Read the number of battens, the actual spacing of the layout, and the boards to buy. Tick the rails box to add a top and bottom rail.
Formula
Battens at both ends: gaps = (wall width - batten width) / spacing, rounded up; battens = gaps + 1
Actual spacing = (wall width - batten width) / gaps
Between only: bays = wall width / spacing, rounded up; battens = bays - 1
Boards to buy = battens with extra / battens cut from one board, rounded up
Wall width is in inches in the formula. If the wall is taller than the board, each batten needs more than one piece and the tool counts the joined pieces.
A 10 foot wall with 2.5 inch battens
The wall is 120 inches wide and the battens are 2.5 inches wide at a spacing of 12 inches. With a batten at each end, the gaps cover 120 - 2.5 = 117.5 inches, and 117.5 / 12 = 9.79, which rounds up to 10 gaps. That means 11 battens at an actual spacing of 117.5 / 10 = 11.75 inches.
With 10 percent extra the count is 12.1, so you would cut 13. Using 8 foot boards for an 8 foot wall, each board makes one batten, so 13 boards. With no end battens the 10 foot wall has 10 bays and 9 battens at exactly 12 inches. Top and bottom rails add 2 x 10 x 1.1 = 22 feet, which is 3 boards.
Choosing the layout
The tool spaces the battens evenly so that no gap is wider than the spacing you ask for, which means the actual spacing is usually a little tighter. Some people prefer to center a window or a focal point and let the end bays differ, which this tool does not do.
A batten at each end gives a clean edge in a corner, while leaving the ends open works for a wall that ends at trim. Mark the layout on the wall with a level line before you fasten anything.
What the count does not cover
The calculator counts battens across the full width and does not subtract windows or doors. The backing boards or sheets that sit behind the battens, nails, adhesive, caulk and paint are not included either. For a quick check on the sheets, use the wall area from the square footage calculator.
Compare with the other wall treatments in the wainscoting calculator and the shiplap calculator, and with exterior coverings in the siding calculator. The baseboard trim calculator covers the trim at the bottom.
Assumptions and limits
- Battens run full height and are spaced evenly across the width.
- The spacing you enter is a maximum, measured center to center.
- The extra percent is your choice and starts at 10 percent as an example.
- Windows, doors, backing sheets and fasteners are not subtracted or counted.
Frequently asked questions
How do I calculate how many battens I need?
Take the wall width minus one batten width, divide by the spacing and round up to get the number of gaps, then add one for a batten at each end. A 10 foot wall with 2.5 inch battens at 12 inches needs 11.
What spacing should I use for board and batten?
That is a design choice, and 12 inches is only an example. Wider spacing looks more open and uses fewer battens, and tighter spacing looks more formal.
Why is the actual spacing smaller than the spacing I entered?
Because the count has to be a whole number of battens. The tool rounds up and then spreads the battens evenly, so the real spacing is never larger than your target.
Do I need rails?
Many designs use a top and bottom rail to frame the battens, but it is a style choice. The checkbox adds the rail length and boards if you want them.