Board and Batten Cut List Calculator

How the board-and-batten spacing is calculated

The useful spacing is the clear opening from one batten edge to the next, not the distance from center to center. Start with the finished span after deciding where the treatment begins and ends. Then measure the actual face width of the trim; a nominal board size is not reliable enough for a layout.

For a wall width W, batten width b, maximum desired clear gap t, and batten count N, the calculator chooses the fewest whole battens that keep the opening at or below your target. With battens flush to both ends:

N = max(2, ceil((W + t) / (b + t)))

g = (W - N × b) / (N - 1)

With equal open margins at the two ends:

N = max(1, ceil((W - t) / (b + t)))

g = (W - N × b) / (N + 1)

Here g is the actual clear gap. Center-to-center spacing is p = b + g. The first flush-end batten starts at zero; the first equal-margin batten starts at g. Every displayed left edge and centerline is calculated from the left boundary independently, so rounding to the nearest sixteenth does not build up across the wall.

How the cut list and stock count work

For vertical cuts of length H from stock length S with saw kerf k, the number of cuts that fit on a board is c = floor((S + k) / (H + k)). Vertical stock boards are ceil(N / c). The cut list shows the kerf allowance between pieces and the unused offcut from a fully used vertical board.

Each full-width rail is planned as its own run. Its board count is ceil(W / S), multiplied by the number of rails. That is intentionally conservative: it does not treat offcuts from one rail as available to another. The spare percentage is applied once, after vertical and rail boards are added, and the final purchase is rounded up to whole boards.

What changes the result most

A smaller target gap or a wider batten increases the count. A longer vertical cut or a wider saw kerf can reduce how many pieces fit on a stock board. Rails can dominate the material order on a wide wall because a rail longer than the stock needs a planned joint for every run.

What this calculator leaves out

This is a decorative layout and purchasing estimate, not a framing or siding design. It does not move battens around windows, doors, outlets, switches, corners, bowed walls, or out-of-square surfaces. It also does not optimize shared offcuts, choose visually appropriate splice locations, or account for fastening, grain matching, paint, caulk, or labor. Check the actual wall and trim, dry-fit the first and last pieces, and keep electrical boxes accessible.

Worked example

For a 144 inch wall, 2 1/2 inch battens, a 16 inch maximum clear gap, and battens at both ends, the count is ceil((144 + 16) / (2.5 + 16)) = 9. The battens occupy 22 1/2 inches, leaving 121 1/2 inches across eight spaces. The actual clear gap is 15.1875 inches, or about 15 3/16 inches, and the center-to-center pitch is 17.6875 inches.

With 48 inch vertical cuts, 96 inch stock, and a 1/8 inch kerf, one stock board yields one vertical cut because two cuts plus the kerf do not fit. Nine vertical boards are needed before spare material. Two 144 inch rails each need two stock boards, so the base order is 13 boards. Adding a 10% whole-board spare allowance gives ceil(13 × 1.10) = 15 stock boards to buy.