Enter the width and height of the room into the calculator, and multiply the sum by 2, then add the circumference of any corners or angles to determine the length of crown molding needed.

Crown Molding Formula

The following formula is used to calculate the length of crown molding needed for a room:

L = 2 * (W + H) + C

Variables:

  • L is the length of crown molding needed
  • W is the width of the room
  • H is the height of the room
  • C is the circumference of any corners or angles in the room

To calculate the length of crown molding needed, multiply the sum of the width and height of the room by 2. Add the circumference of any corners or angles in the room to the result.

What is a Crown Molding?

Crown molding is a type of decorative trim used to add visual interest to a room. It is typically installed where the walls meet the ceiling, creating a distinctive and elegant transition between the two. Crown molding is often ornate, featuring complex profiles that may include curves, angles, and other architectural details. It is made from various materials such as wood, plaster, or polyurethane, and can be painted or stained to match the room’s decor. In addition to its aesthetic appeal, crown molding can also help to hide any imperfections or unevenness where the wall and ceiling meet. It is a popular design feature in both traditional and contemporary interiors.

How to Calculate Crown Molding?

The following steps outline how to calculate the Crown Molding for a project.


  1. First, measure the length of the wall where the crown molding will be installed (in inches).
  2. Next, measure the height of the wall where the crown molding will be installed (in inches).
  3. Next, calculate the perimeter of the room by adding the length of all the walls (in inches).
  4. Next, calculate the linear footage of crown molding needed by multiplying the perimeter of the room by 1.1 (to account for waste).
  5. Finally, round up the linear footage to the nearest whole number to determine the total length of crown molding needed.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Length of the wall (in inches) = 120

Height of the wall (in inches) = 96