Wainscoting covers the lower part of a wall, typically one-third of the wall height (32–36 in on an 8 ft wall). Picture-frame and raised-panel styles look best when every panel is the same width, separated by equal stiles. Start from the width you would like and let the calculator round to a whole number of panels.
How to use the Wainscoting Calculator
- Wall width
- Wainscot height
- Stile width
- Top rail width
- Bottom rail width
- Target panel width
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the wall width, the wainscot height, the stile width, top and bottom rail widths and your target panel width.
Tips for an accurate estimate
- Take measurements at floor level and at the ceiling – walls and rooms are often slightly out of square.
- Use the manufacturer’s coverage, spacing and installation data when it differs from the typical values here.
- Keep a little extra of every finish material for touch-ups and repairs later.
- Check local building codes and permits before structural, electrical, plumbing or gas work.
Common mistakes to avoid
- Sizing heating or cooling equipment by area alone when insulation, windows and climate make a big difference.
- Buying too little paint, stain or flooring and ending up with mismatched batches.
- Overlooking the extra material for steps, railings, gables and trim.
Inputs explained
| Field | What to enter |
|---|---|
| Wall width | Units: ft, m, in, yd, cm |
| Wainscot height | Units: in, cm, mm, ft, m |
| Stile width | Units: in, cm, mm, ft, m |
| Top rail width | Units: in, cm, mm, ft, m |
| Bottom rail width | Units: in, cm, mm, ft, m |
| Target panel width | Units: in, cm, mm, ft, m |
What each result means
- Number of panels = max(round(([Wall width] – [Stile width])÷([Target panel width] + [Stile width])), 1)
- Panel width = ([Wall width] – ([Number of panels] + 1)×[Stile width])÷[Number of panels]
- Panel width (fraction) = [Panel width]
- Panel height = [Wainscot height] – [Top rail width] – [Bottom rail width]
- Stiles = [Number of panels] + 1
- Trim length (stiles + rails) = ([Number of panels] + 1)×([Wainscot height] – [Top rail width] – [Bottom rail width]) + 2×[Wall width]
- Paintable area = [Wall width]×[Wainscot height]
Example values
How the main result changes when Wall width changes and everything else stays at the example values above:
| Wall width (ft) | Number of panels |
|---|---|
| 6 | 3 |
| 9 | 5 |
| 12 | 7 |
| 15 | 8 |
| 18 | 10 |
| 24 | 13 |
Formula
Panels n = round((W − s) ÷ (target + s))Panel width = (W − (n + 1) × s) ÷ nPanel height = wainscot height − top rail − bottom railWorked example
Inputs — Wall width: 12 ft; Wainscot height: 36 in; Stile width: 3.5 in; Top rail width: 3.5 in; Bottom rail width: 5.5 in; Target panel width: 18 in.
Results — Number of panels = 7; Panel width = 16.571 in; Panel width (fraction) = 16 9/16; Panel height = 27 in; Stiles = 8; Trim length (stiles + rails) = 42 ft; Paintable area = 36 ft².
Frequently asked questions
How high should wainscoting be?
About one-third of the wall height: 32–36 in on 8 ft walls, up to 48–54 in in tall rooms.
How wide should wainscot panels be?
Usually 12–24 in; choose a width that divides the wall evenly.
How do I handle outlets and windows?
Lay out the panels around large features first, then adjust the target width so panels stay equal.
What formula does the Wainscoting Calculator use?
Panels n = round((W − s) ÷ (target + s)).