How to Measure Crown Molding Like A Pro

Written by Milan Jara on 14th Jul 2022

Crown Moldings

Crown molding adds architectural interest and flair, but proper installation requires accurate measurements. Read on to learn how to measure crown molding like a professional.

Crown molding blends the look of your ceiling and walls to create alluring visuals and, better yet, improve the aesthetic value of your home. Crown molding installation requires patience and effort to nail the perfect angles. Precise measurements and smooth cuts are the foundational steps in ensuring you install the moldings like a pro.

In this article, you’ll learn how to measure crown molding and avoid material wastage or the common gaps most DIYers leave. We'll wrap this up with recommendations on the best crown molding for dressing up your home.

Crown Moldings, Angles, and Corners

Before measuring, you should understand the angles and joints that crown moldings form. Crown molding sits on the ceiling and the drywall. Most moldings come in 8-, 10-, and 12-foot lengths. You will need to cut and trim moldings to sizes that match your walls and ceilings.

It’s important to know the type of cuts you will make to simplify measuring. Generally, moldings form a scarf joint, coped joint, or miter joint. But you can try out different types of joints to your preference.

If you are working on an inside corner meeting an outside corner, you will need to make a scarf joint which means different measuring techniques. Knowing the inside and outside corners is equally important.

You can designate the inside corners as the ones facing away from the room's interior and the outside corners to be the ones facing towards the room's interior. Best practices indicate you should measure the inside-corner-to-inside-corner, especially since you will use a miter saw to cut the crown molding during installation.

With the knowledge of inside and outside corners, you can proceed to measure the required size.

Crown Moldings

Measuring Crown Molding

Like any other woodworking job, you must set up perfectly for streamlined measuring. Measuring crown molding may require two pairs of hands. To put the adage into practice, "measure twice, cut once," you need to double-check the measurements and practice with scrap boards to ensure precise cuts on the actual crown molding. Follow our five-step procedure to measure crown molding.

1. Gather Equipment

First, you need protective equipment, including goggles, gloves, and a mask. You may not necessarily need them for measuring, but you will need them in the installation process. Here are the supplies you need for this job:

  • Tape measure
  • Protractor or angle finder
  • Woodworking pencil
  • Step ladder
  • Writing surface

2. Measure the Walls and Ceiling

Crown moldings usually have a 38, 42, or 45 degree spring angle. The wall and ceiling length determine the spring angle. Measure the length of the walls and the ceilings using a tape measure. It is best to draw a sketch of the room on paper and write the precise lengths on the diagram.

Measure from the ceiling across the wall to where the molding will end. Measure again from the ceiling where the back of the molding meets it and measure the wall length downwards.

If the wall has the longest measurement, the crown molding will have a 38-degree spring angle.

If the ceiling measurement is the longest, then the crown molding is at a 52-degree spring angle.

If the measurements are the same, it is a 45-45-degree spring angle.

You will use these angle markings to set the miter saw and cut it. To ascertain your measurements, proceed to the next step.

3. Measure the Angles

Rarely are wall and ceiling angles perfectly perpendicular. The angles are usually a couple of degrees off; you should factor this in to avoid unsightly crown molding gaps.

Using your angle finder tool, place the blades against the edges of the wall corner you are measuring. Angle finder tools have a wide range of motion and fit inside and outside corners.

Measure the degree of the wall corner and then use an angle chart to determine the miter-bevel angle. The digital version of the angle finder will generate the miter angle for you, and you will not need an angle chart.

Crown Moldings

4. Measure the Length of the Molding for Corners

How you measure an inside wall corner is different from how you measure an outside corner. To get accurate measurements, measure the wall length at ceiling height from corner to corner. You can use the inside-to-inside corner technique.

For the outside corner, the wall-to-corner length will be the short point for the crown molding on the angle. For the inside corner, the length will be the long point for cutting inside corners at 45 degrees.

Mark the correct lengths on the sketch. As good practice, round off measurements to the nearest foot. If you measure 8.3 inches, round it off to 9 feet. You can trim the extra material during installation, but you can't make up for a short piece unless you use caulk to fill the gaps, which detracts from the quality of the crown molding.

Take the total measurement you need and add 10% more when buying the crown moldings. Most moldings are wooden, but you can use urethane crown moldings that are a cinch to cut. Most people have problems with cutting inside corners since walls are often not perfect at 45 degrees. For such walls, you can cope with the moldings.

5. Compile Measurements

Using your sketch, draw a detailed layout of the house. You can do a second measurement and do the average to determine the required length for the crown molding and corners. If you intend to install the crown moldings yourself, you will need the sketch to cut and trim moldings to size easily. If you have wall paneling, you may need to leave a gap equal to the crown molding width above the paneling when installing the molding. The crown molding will fill the gap.


Finding the right crown molding is equally important as getting precise measurements. Check out our glam-looking crown moldings to update your vertical space. Accurate measurements and precise cuts will help you achieve the best crown trims to match your walls and ceilings.

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