Board and Batten Calculator
Plan a board and batten wall in minutes. Enter your wall size and batten width, and this calculator works out how many battens you need, the exact equal gap between them, where to mark each one and how many boards to buy. It also draws your wall to scale, and an exterior siding mode counts boards and battens for siding projects.
Your results will appear here.
How to use the board and batten calculator
- Choose the project type. Pick Interior accent wall for battens fastened over drywall, or Exterior siding for vertical boards with battens covering the gaps.
- Measure the wall. Enter the width and height in feet and inches (or switch to metric). Measure at the top and bottom of the wall and use the smaller number.
- Enter the actual batten width. Lumber is sold by nominal size, so a 1×4 is really 3-1/2 in wide. The help text under the field lists common sizes.
- Set the layout. Type the gap you would like between battens, or the number of vertical battens you want. The calculator adjusts the gap so every space is exactly equal.
- Add the details. Choose whether you want battens at both ends, a top rail, a baseboard and horizontal rows for a grid look.
- Read your results. You get the batten count, the exact gap, center-to-center spacing, marking positions, total length and the number of boards to buy, plus a drawing of the finished wall.
How the spacing is calculated
Most people pick a gap they like, then find that it does not divide evenly into the wall. The calculator fixes that by finding the batten count that gets closest to your target gap, then sharing the leftover space equally between every gap.
With a batten at each end of the wall, there is one fewer gap than there are battens:
Gap = (Wall width − Number of battens × Batten width) ÷ (Number of battens − 1)
Without end battens, the wall edges act as the first and last gap, so you divide by the number of battens plus one instead.
Worked example
A wall is 12 ft wide (144 in) and you want 1×4 battens (3-1/2 in actual) about 16 in apart, with a batten at each end.
- Battens: (144 − 3.5) ÷ (3.5 + 16) = 7.2, rounded to 7, plus the first batten = 8 battens
- Exact gap: (144 − 8 × 3.5) ÷ 7 = 16.57 in, or 16-9/16 in
- Center-to-center spacing: 3.5 + 16.57 = 20-1/16 in
Mark the first batten center 1-3/4 in from the left edge, then measure 20-1/16 in to each next center. The calculator lists these marks for you.
Common board and batten sizes
| Nominal size | Actual width | Typical use |
|---|---|---|
| 1×2 | 1-1/2 in | Slim battens on small walls and half-wall wainscoting |
| 1×3 | 2-1/2 in | Classic interior battens and grid patterns |
| 1×4 | 3-1/2 in | Bold interior battens and top rails |
| 1×6 | 5-1/2 in | Top rails and chunky farmhouse styles |
| 1×8 | 7-1/4 in | Exterior boards |
| 1×10 | 9-1/4 in | Exterior boards (common choice) |
| 1×12 | 11-1/4 in | Wide exterior boards |
If you use MDF strips or ripped plywood instead of lumber, measure the real width with a tape and enter that number.
Popular gap choices for accent walls
There is no single correct gap. Many accent walls use gaps between 12 in and 24 in. Narrow walls usually look best with gaps toward the low end, while long walls can take wider spacing. Try a few values in the calculator and look at the drawing before you buy material.
Interior accent wall or exterior siding?
Interior accent walls are usually made by nailing and gluing battens directly onto painted drywall. Some builders add thin plywood or hardboard panels first for a smoother finish. The look comes from the shadow lines between the battens, so even spacing matters more than anything else.
Exterior siding uses wide vertical boards with a small gap between them, then a narrower batten over each gap. The batten should overlap each board by at least 1/2 in. Use materials rated for exterior use, follow the manufacturer’s fastening schedule and keep the bottom of the siding clear of soil and roofing.
In siding mode the calculator counts the boards needed to cover the wall width, adds one batten for every gap and tells you how many pieces to buy at the board length you choose.
Tips for a clean, professional layout
- Find a focal point. If the wall has a centered bed, window or TV, check whether a batten or a gap lands in the middle. Change the batten count by one to move it.
- Work around outlets and switches. Mark them on the wall before you cut. A batten that lands on an outlet can be notched, or you can shift the whole layout slightly.
- Use a level, not the ceiling. Ceilings and floors are rarely perfectly straight. Plumb each vertical batten with a level instead of measuring down from the ceiling.
- Prime and paint first. Painting battens before you install them saves time. Fill nail holes and caulk the edges afterward, then add the final coat.
- Buy extra. The default 10% waste allowance covers bad ends, splits and cutting mistakes.
Frequently asked questions
How far apart should board and batten be?
For interior accent walls, many people choose gaps between 12 in and 24 in. Wider battens and longer walls can handle wider gaps. The best approach is to pick a target, let the calculator make every gap equal and check the drawing before you cut.
How many battens do I need for a 12-foot wall?
With 1×4 battens (3-1/2 in) and a target gap of about 16 in, a 12-foot wall needs 8 vertical battens, with a batten at each end. The exact gap is 16-9/16 in. Different batten widths or gaps change the count, so enter your own numbers above.
Should there be a batten at each end of the wall?
Most accent walls have a batten at both ends because it frames the wall neatly where it meets the corners. If your wall ends at a door casing or another trim piece, you may prefer to start with a gap instead. Untick the end battens option to see that layout.
What is the difference between board and batten and wainscoting?
Board and batten usually runs the full height of the wall with vertical battens. Wainscoting covers only the lower part of the wall, often finished with a horizontal cap. You can plan a wainscot-style wall here by entering the wainscot height as the wall height.
How do I handle a window or door on the wall?
Plan the full wall first so the spacing stays consistent, then stop each batten at the window or door trim. The calculator does not subtract openings, so you may end up with a few spare boards.
Do I need to hit studs?
Battens on an interior wall are light, so construction adhesive plus brad or finish nails into the drywall usually holds them. Nailing into studs where possible adds strength. Exterior battens and boards must be fastened according to the siding manufacturer's instructions.
Sources and methodology
The formulas on this page were written and checked by the HomeQuantly Team against the worked examples shown above. Results are estimates for planning; always confirm measurements on site before you buy materials.