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Board and Batten Spacing Calculator

Lay out equal spaces between decorative battens with a batten at each end. Enter wall width, trim width, height and the largest clear gap you want.

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Includes the waste margin explained below. Check your product label for coverage and sizes.

Plan an evenly spaced decorative wall

Board and batten treatment divides a wall into open bays separated by vertical strips of trim. This layout calculator begins with a strip at each end, then chooses enough intermediate strips that no clear bay exceeds your requested maximum. It solves for equal gaps rather than repeatedly marking a fixed distance and leaving an odd narrow opening at the far corner. The calculation is for decorative internal trim on one uninterrupted wall. It does not design structural wall members or weatherproof external cladding.

Separate clear gaps from centre spacing

Bays = ceil((wall width − batten width) ÷ (maximum gap + batten width)); battens = bays + 1

After counting the battens, their combined face widths are subtracted from the wall. The remaining width is divided by the number of bays to give the equal clear gap. Adding one batten width gives centre-to-centre spacing. Metric wall measurements use metres and trim measurements use millimetres; imperial wall measurements use feet and trim measurements use inches. Actual face width matters: a nominal board label may not match the finished strip you intend to attach. The tool rejects a wall that cannot fit two end strips or a proposed bay layout with negative clear space.

Worked layout across a three-metre wall

A wall 3 metres wide is 3,000 millimetres across. With 50 millimetre battens and a maximum clear gap of 400 millimetres, the bay calculation is ceil((3,000 − 50) ÷ (400 + 50)) = 7. That means eight vertical strips, including the two ends. They occupy 400 millimetres together, leaving 2,600 millimetres for seven openings. Each opening is 371.43 millimetres wide and the centre spacing is 421.43 millimetres. At a vertical strip height of 1.2 metres, the net trim requirement is 8 × 1.2 = 9.6 linear metres before cutting losses.

Mark the layout before cutting

Draw both end strips on the wall or a scaled sketch before transferring centre marks. If the neighbouring wall already has a corner strip, decide whether it belongs inside your measured width and maintain that convention throughout. Doors and windows break the equal-bay pattern; calculate uninterrupted runs separately or adjust the layout on a drawing. Horizontal rails, cap mouldings, skirting and backing panels are excluded from the vertical trim result. Net linear length is not a stock-board purchase count, because kerf, defects and cut combinations can prevent every offcut from being useful. Dry-position strips or use removable marks to judge proportions, then confirm the actual gap fits the furniture, outlets and edges around the feature wall.

Frequently asked questions

Are end battens included?

Yes. The count includes one full-width vertical strip at each end and all intermediate strips required for the equal-bay layout.

What does maximum clear gap mean?

It is the largest open distance between adjacent batten faces. The final equal gap can be smaller because the number of bays must be an integer.

Is centre spacing the same as the opening?

No. Centre spacing equals clear gap plus one actual batten width. Use the displayed value that matches how you make your marks.

Does this count horizontal rails?

No. Vertical trim length includes only the upright pieces at the entered height. Add rails, caps, backing and cutting losses separately.

How should I handle a door?

Treat uninterrupted sections individually or draw a full elevation. This simple layout has no openings and cannot align trims around door or window edges automatically.

Last reviewed: 2026-10-03 · How we calculate