Picture Frame Molding Calculator for Wainscoting

Picture frame wainscoting is a row of molding frames on a painted wall. Enter the wall and the frame width you like. You get an even frame count, the frame size and the molding to buy.

Your shopping list

7Frames across the wall
7Frame molding pieces to buy
16.57 inFrame width for an even fit
  • Frame heightBetween the top and bottom rails27 in
  • Stiles8
  • Stile pieces to buy3
  • Top rail pieces to buy2
  • Frame molding in totalIncludes extra55.92 ft
  • Center to center of frames20.07 in

The molding runs around the inside of each frame, with mitered corners. Pieces include 10% extra.

How to use the Picture Frame Wainscoting Calculator

  1. Measure the wall length and the height from the floor to the top of the top rail.
  2. Enter the rail, baseboard and stile widths, and the frame width you like.
  3. Pick the board length you buy. Leave the extra at 10%.
  4. Use the even frame width, so the first and last frames match.

The math behind it

Frames = (wall length – stile) / (frame width + stile), rounded
Even frame width = (wall length – (frames + 1) x stile) / frames
Frame height = height – top rail – bottom rail
Molding = frames x 2 x (frame width + frame height)

A worked example

What we typed in

  • Wall length: 15 ft
  • Wainscoting height: 40 in
  • Top rail width: 3.5 in
  • Bottom rail or baseboard height: 5.5 in
  • Stile width (the upright boards): 3.5 in
  • Frame width you would like: 18 in
  • Length of boards you buy: 8 ft
  • Extra for mistakes and cuts: 10%

What we got

  • Frames across the wall: 8
  • Frame molding pieces to buy: 10
  • Frame width for an even fit: 18.56 in
  • Frame height: 31 in
  • Stiles: 9
  • Stile pieces to buy: 4
  • Top rail pieces to buy: 3
  • Frame molding in total: 72.69 ft
  • Center to center of frames: 22.06 in

For a related part of your project, use the Rigid Foam Board Insulation Calculator.

Tips from the job site

  • Draw the layout on the wall with a level and painter’s tape before you nail anything.
  • Miter the corners at 45 degrees and fill the joints with caulk.
  • Keep the frames the same size across one wall, even if the wall is long.

Common questions

How far apart should the frames be?

The space between two frames is the stile width. 3 to 4 in is common. The calculator uses your stile width.

What if the frame count is not a whole number?

The tool rounds to the nearest whole frame and then changes the frame width so every frame is equal.

Is the molding length exact?

It is a careful estimate. Miter cuts waste a little, so keep the extra at 10% or more.

See all Wall Calculators.

Last checked: (worked example and form display).