Find equal wainscoting panel widths
Clear wainscoting panel width equals (wall width − total stile width) divided by the number of panels. A 144-inch wall with five panels and six 3.5-inch stiles gives 24.6-inch openings. Choose a 20-inch target instead and the calculator selects six panels, displayed as 19 15/16 inches each. This single-wall layout excludes openings, joinery and material movement allowances.
Panel width p = (W − (n+1)s) ÷ n
There are n panels and n+1 stiles. The equivalent expression is (W−s)÷n−s. Panel height h = chair-rail top − cap allowance − top rail − bottom rail − existing baseboard.
Choose panels or picture frames
A recessed or raised panel layout divides the wall into clear openings between solid stiles. This calculator lists stile lengths between the top and bottom rails. It does not size a floating center panel for grooves, rebates or seasonal movement; those dimensions depend on the construction method.
A picture-frame or shadow-box layout places molding inside each reserved opening. The outside frame size is clear panel size minus twice the inset. The cut list uses four 45°-mitered pieces per frame, measured to the outside long point. The entered molding width must leave a positive inside opening.
Choose the chair-rail height deliberately
The 1/3-wall preset gives 32 inches on a 96-inch wall. It is a design option, not a code requirement or a promise that it fits your room. Use custom height to coordinate with windows, outlets, switches and furniture. The cap field is the vertical allowance deducted in this formula; check your actual profile before measuring the opening.
Optional proportions to compare
For visual comparison, try 32–36-inch or 40–66-inch heights, 16–24-inch panel openings, a 2–3-inch upper rail or a 7–8-inch lower rail. These are design starting ranges, not minimums, maximums or building-code requirements. Inspect openings narrower than 12 inches in the drawing, and check your actual trim profiles. See the methods and reference notes.
Read the cut allocation before buying
Choose the stock lengths actually available. The first-fit decreasing estimate keeps different material widths separate, includes saw kerf on each cut piece, and lists optional spare boards independently. Existing baseboard is deducted from the height and is not counted as a new material. Backing-panel sheet sizes and adhesive, nail or paint quantities are outside this estimate.
For a wall defined by vertical strips and clear gaps, calculate board and batten spacing. Read the calculation methods and references for the boundary between geometry and installation decisions.
Questions before you cut
How do I size wainscoting?
Choose the height, rail sizes and either a panel count or target clear panel width. With width W, n panels and stile width s, clear panel width = (W − (n+1)s) / n. A 144-inch wall, five panels and 3.5-inch stiles gives 24.6-inch clear openings. This excludes joinery allowance and backing-panel machining.
How do I calculate wall panelling spacing?
Reserve the end and intermediate stiles first, then divide the remaining width equally between the panels. The position table gives every stile left edge and centerline from the left end of the wall. Use the unrounded formula for layout; displayed fractions round independently to the nearest 1/16 inch.
How tall should wainscoting be?
The default preset is one third of the entered wall height: a 96-inch wall gives a 32-inch chair-rail top. This is a layout starting point, not a building rule. Choose custom height to coordinate with windows, switches and furniture. Subtract cap, upper rail, lower rail and existing baseboard to find the clear panel height.
What is typical wainscoting spacing?
There is no single spacing that fits every room. Pick a panel count or target width and inspect the resulting proportions. For a 144-inch wall, 3.5-inch stiles and a 20-inch target, this calculator selects six panels, each 19.9167 inches wide, displayed as 19 15/16 inches. Openings and obstacles need a separate check.
Wainscoting vs board and batten—what is the difference?
Wainscoting is the broader treatment of the lower portion of an interior wall and can include framed or solid-panel layouts. Board and batten emphasizes vertical strips separated by clear gaps and may run part-height or full-height. Use the board and batten tool for batten positions, and this tool for panel openings and stile marks.