Wainscoting Calculator: Panel Size, Rail Height and Boards
Enter the wall size, the rail height and your trim sizes to get equal panels, a tape mark for each stile and the boards to buy.
Your measurements
Measure the wall, pick a rail height and the trim. Everything updates as you type.
Wall
Corner to corner just above the baseboard. Measure at two heights and use the smaller figure.
Common widths
Floor to ceiling. Used for the rail-height rules of thumb and the drawing.
Common heights
Rail height
Rules of thumb, not a standard: about a third of the ceiling height is the classic chair-rail look; two thirds or more suits tall paneling. Try it with painter's tape first.
Share of the ceiling
Frame
Panels roughly as wide as they are tall, or a little narrower, usually look balanced.
Measure a board: a 1×4 is 3-1/2 inches wide.
Common boards
The horizontal board at the top of the panels.
Common boards
The bottom of each panel frame. Enter 0 to frame the panels without a baseboard.
A ledge or chair-rail moulding along the top. It adds one more run to buy.
Buying
Check what your store stocks. Longer boards mean fewer joints in the rails.
Added to the rails for miscuts and joints. 10% is a common allowance, not a rule.
Results
Panel width
= 625 mm
5 equal panels between 6 stiles, with a stile in each corner.
- Panel height
- 23"
- = 584 mm
- Also the length to cut each stile
- Stile spacing
- 28 1/8" (714 mm)
- Left edge to left edge (on center)
- Boards to buy
- 6× 8 ft
- 35.5 linear ft of trim before waste
Stile marks
Hook the tape on the left corner and mark both edges of each stile. Rounded to 1/16 inch.
| Stile | Left edge | Right edge |
|---|---|---|
| 1 | 0" (0 mm) | 3 1/2" (89 mm) |
| 2 | 28 1/8" (714 mm) | 31 5/8" (803 mm) |
| 3 | 56 3/16" (1427 mm) | 59 11/16" (1516 mm) |
| 4 | 84 5/16" (2141 mm) | 87 13/16" (2230 mm) |
| 5 | 112 3/8" (2855 mm) | 115 7/8" (2944 mm) |
| 6 | 140 1/2" (3569 mm) | 144" (3658 mm) |
Cut list and boards
Boards 8 ft long. Rails get 10% extra; stiles are counted by cuts (4 per board).
| Part | Board width | Pieces | Linear ft | Boards |
|---|---|---|---|---|
| Baseboard | 5 1/2" (140 mm) | 2 lengths joined for 144" (3658 mm) | 12 | 2 |
| Top rail | 3 1/2" (89 mm) | 2 lengths joined for 144" (3658 mm) | 12 | 2 |
| Stiles | 3 1/2" (89 mm) | 6 × 23" (584 mm) | 11.5 | 2 |
How this was calculated
Plain arithmetic, with your numbers. No reference data is involved.
How this was calculated
Plain arithmetic, with your numbers. No reference data is involved.
Step 1: Panel height
panel height = rail height − baseboard − top rail
= 32" − 5.5" − 3.5"
= 23" (23")The rail height is measured from the floor to the top of the top rail. The stiles are cut to this length so they fit between the baseboard and the top rail.
Step 2: Panel width
panel width = (wall − stiles × stile width) ÷ panels
= (144" − 6 × 3.5") ÷ 5 = (144" − 21") ÷ 5
= 24 5/8" (24.6")A stile sits in each corner, so 5 panels need 6 stiles: one more than the panels.
Step 3: Stile marks
left edge of stile n = (n − 1) × (panel width + stile width)
= (n − 1) × (24.6" + 3.5") = (n − 1) × 28.1"
= last stile from 140 1/2" to 144"Mark every stile from one tape hooked on the left corner, rather than gap by gap, so small errors do not add up. The last stile should end in the right corner.
Step 4: Boards for the stiles
boards = stiles ÷ stiles per board, rounded up
= 6 ÷ 4 (8 ft boards, 23" pieces, 1/8" saw kerf)
= 2 boardsStiles are cut whole from each board, so the count goes by cuts, not by length. Offcuts shorter than a stile are left over.
Step 5: Boards for each rail
boards = wall × (1 + waste) ÷ board length, rounded up
= 144" × 1.1 ÷ 96"
= 2 boardsThe same count applies to the baseboard and to a cap rail. Where a run is longer than one board, join the pieces with a scarf joint over a stud.
In short
Panel width = (wall − stiles × stile width) ÷ panels, and panel height = rail height − baseboard − top rail. On a 144" wall with 5 panels, 3.5" stiles and a 32" rail, each panel is 24 5/8" wide and 23" high.
The drawing is to scale and updates as you type, so you can try rail heights and panel counts before you cut anything.
Rail heights for common ceilings
Plain fractions of the ceiling height, to the nearest 1/2 inch. These are rules of thumb designers use, not a building standard; see the height proportions guide for when each one suits a room.
| Ceiling | 1/3 (chair-rail look) | 2/3 (tall paneling) | 3/4 |
|---|---|---|---|
| 8 ft (96") | 32" | 64" | 72" |
| 9 ft (108") | 36" | 72" | 81" |
| 10 ft (120") | 40" | 80" | 90" |
| 12 ft (144") | 48" | 96" | 108" |
Worked example: 12 ft wall, 5 panels, 32" rail
A 5.5" baseboard, 3.5" top rail and 3.5" stiles (1×6 and 1×4 boards), with 8 ft boards and 10% extra on the rails.
Step 1: Panel height
panel height = rail height − baseboard − top rail
= 32" − 5.5" − 3.5"
= 23" (23")The rail height is measured from the floor to the top of the top rail. The stiles are cut to this length so they fit between the baseboard and the top rail.
Step 2: Panel width
panel width = (wall − stiles × stile width) ÷ panels
= (144" − 6 × 3.5") ÷ 5 = (144" − 21") ÷ 5
= 24 5/8" (24.6")A stile sits in each corner, so 5 panels need 6 stiles: one more than the panels.
Step 3: Stile marks
left edge of stile n = (n − 1) × (panel width + stile width)
= (n − 1) × (24.6" + 3.5") = (n − 1) × 28.1"
= last stile from 140 1/2" to 144"Mark every stile from one tape hooked on the left corner, rather than gap by gap, so small errors do not add up. The last stile should end in the right corner.
Step 4: Boards for the stiles
boards = stiles ÷ stiles per board, rounded up
= 6 ÷ 4 (8 ft boards, 23" pieces, 1/8" saw kerf)
= 2 boardsStiles are cut whole from each board, so the count goes by cuts, not by length. Offcuts shorter than a stile are left over.
Step 5: Boards for each rail
boards = wall × (1 + waste) ÷ board length, rounded up
= 144" × 1.1 ÷ 96"
= 2 boardsThe same count applies to the baseboard and to a cap rail. Where a run is longer than one board, join the pieces with a scarf joint over a stud.
Before you cut
- Snap a level line for the top of the rail with a laser or a long level. Floors are rarely level, so measure each stile in place.
- Use the measured width of your boards. A 1×4 is 3-1/2 inches wide, and some boards are milled narrower.
- Check where stiles land against outlets, switches and window trim. One more or one fewer panel often clears them.
Wainscoting: common questions
Height, panel size, stile length and boards.
How high should wainscoting be on an 8 foot ceiling?
There is no standard height. A common rule of thumb puts the top of the rail at about a third of the ceiling height, 32 to 36 inches on an 8 ft (96 inch) ceiling, for a classic chair-rail look, and at about two thirds (64 inches) for tall paneling. Many designers avoid exactly half (48 inches). Mark a couple of heights with painter's tape and see which you prefer.
How do I work out the width of wainscoting panels?
Multiply the number of stiles by the stile width and take that from the wall width, then divide what is left by the number of panels. With a stile in each corner there is one more stile than panels. A 144 inch wall with five panels and six 3-1/2 inch stiles leaves 123 inches, so each panel is 24-5/8 inches wide.
How long do I cut the stiles?
Each stile fits between the top of the baseboard and the bottom of the top rail, so its length is the rail height minus the baseboard height minus the top rail width. That is also the panel height. Floors are rarely level, so measure each stile in place before cutting it.
How many boards do I need for wainscoting?
Count the rails and the stiles separately. The baseboard, top rail and any cap rail each run the full width of the wall, so they are bought by length plus a waste allowance. The stiles are cut whole from boards, so count how many fit on one board and divide. The calculator does both for the board length you choose.