What This Calculator Covers
The calculator takes your wall width, wall height, and batten face width and returns exact spacing, a precise batten count, and installation marks — the left edge, center, and right edge of every batten — measured individually from the left wall corner. These absolute positions prevent the measurement drift that accumulates when you step-measure from the previous mark across a long wall.
From there, the results split across six tabs. The Marks tab gives you the wall layout. The Cut List shows what lengths to cut and how many pieces of each. The Stock tab assigns every cut to a specific physical board to minimize the number of boards you need to buy. The Materials tab summarizes total linear footage with your chosen waste allowance applied. The Shopping List formats everything as a clean, copy-ready summary for the lumber yard. The Cost tab lets you enter current local prices for a material cost estimate. You can work through all six in a single session, going from wall dimensions to shopping list without switching tools.
The calculator handles interior accent walls and wainscoting. For wainscoting, enter your panel height — not the full wall height — as the wall height input, and the battens are cut to that dimension. It does not generate exterior siding specs; fastener types, flashing, clearances, and moisture management for exterior work are product-specific and must come from the manufacturer's documentation.
Inputs — What to Enter and Why
Wall width is the most consequential input. Measure at three heights (near the floor, at mid-height, near the ceiling) and use the shortest measurement. Walls in older construction often vary by a quarter inch or more from top to bottom; using the shortest measurement ensures the layout fits at every point. Wall height for full-height installations is measured from the top of the baseboard to the ceiling or the bottom of the crown molding.
Batten face width must be the actual milled dimension, not the nominal size on the label. A 1×4 board is 3.5" wide, not 4"; a 1×3 is 2.5". Using the nominal size throws the gap calculation off by 0.5" per batten — across 9 battens that's 4.5" of accumulated error, and the layout will not fit the wall correctly. The preset buttons (1×2, 1×3, 1×4, 1×6) fill in the correct actual widths. If you're using a non-standard product, measure the board itself before entering anything.
Advanced Options adds top rail, bottom rail, and chair rail — each independently enabled with its own face-width field. These add to the cut list and material totals. Waste Allowance (5%, 10%, or 15%) and Stock Board Length control purchase quantities and board count. For most single-wall projects, 10% waste is reasonable; increase to 15% for walls with multiple openings that generate short off-cuts below the reusable length threshold.
Multiple Walls, Openings, and Sharing
The "+ Add Wall" button adds a new wall to the project, up to 8 walls total. Each wall is configured independently with its own width, height, and opening list. Batten counts, linear footage, and cost totals are summed across every wall in the Materials, Shopping List, and Cost tabs, producing one complete purchase plan for an entire room.
The opening tool handles doors, windows, fireplaces, archways, cabinets, and fixtures. For each opening, enter its position from the left wall edge and its width. Openings can be configured as span-breaks — where the layout grid passes across the opening and battens that land within it are simply skipped — or as obstacles, where the layout ends on each side of the opening independently. Once you have a layout you're satisfied with, the Copy Link button encodes the entire project state into a URL: all walls, dimensions, openings, settings, and unit system. Bookmark it or share it, and the full layout reopens exactly as you left it.
Unit System
The Unit System toggle switches the calculator between Imperial and Metric. Imperial mode parses feet-and-inches (12'6"), plain decimal inches (150"), and fractions (12'5 3/4"). Metric mode accepts millimeters, centimeters, or meters — 3660mm, 366cm, and 3.66m all work for the same dimension. Results display in the matching system. The calculation engine works internally in decimal inches and converts only at the input and output boundaries, so there is no accumulated rounding error when you switch systems mid-project.
What Is Board and Batten?
Board and batten is a vertical wall treatment where narrow strips of trim — the battens — are applied directly to a flat wall surface, with horizontal rails framing the top and bottom. In standard interior installations, the drywall itself acts as the background; the battens are applied over it. The assembly is caulked at every joint, primed, and painted as a single surface. The result is a dimensional, textured wall that reads as built-in rather than applied.
Full-height board and batten runs from the baseboard to the ceiling as a complete wall treatment. Wainscoting is board and batten applied only to the lower portion of the wall — typically 36" to 48" high — with a cap rail at the top separating the paneled zone from the painted wall above. Both formats use identical spacing calculations; the only difference is batten length and whether rails are included in the plan. This calculator handles both configurations through the same input panel.