What this calculator does
The wainscoting calculator finds the total wall area and number of panels needed to install wainscoting around the lower portion of a room’s walls.
The formula
The room’s wall perimeter is 2 x (length + width). Subtracting the total width of any doorways (which don’t need wainscoting) gives the usable perimeter. Multiplying that by the wainscoting height (converted to feet) gives the total area, and dividing the usable perimeter in inches by your panel width, rounded up, gives the number of panels to buy.
This estimate treats the room as a simple rectangle and doesn’t account for corner trim, chair rail, or cutting around outlets — add a small buffer of extra panels for those details.
Last reviewed August 2026