Crown moulding adds an excellent decorative accent to any home's interior, increasing visual appeal and home value. There are numerous crown moulding materials, such as wood or plaster, that can be used depending on your preferences and home design. 

When it comes to choosing a particular style, you will need to decide on the spring angle you want for the design. Picking the spring angle is a crucial part of the installation process, so it's best to be informed on this topic. This article will cover everything you need to know about a crown moulding’s spring angle. 

What is a Spring Angle? 

The spring angle is a crucial indicator of the crown design often produced by manufacturers. When holding a piece of the moulding firmly against a wall, the spring angle is measured from the back of the moulding to the wall. 

These angles differ depending on the design, but the three most common are: 

• 38°
• 45°
• 52°

If you purchase stock crown moulding, they will typically have one of these spring angles. However, the most common style is made with a 38° spring angle measured from the bottom of the moulding to the wall. It is also worth noting, the spring angle for “crown” is also customizable depending on the homeowner's needs. 

How to Determine the Spring Angle 

Before any crown moulding installation project, you should measure the spring angles of each piece. If you use the wrong spring angle, you could have problems during installation. The crown moulding will not align properly, even if there is only a slight difference in the angle.  

There are a few ways to measure the spring angle. The first method uses a specialized digital angle finder to determine the spring angle. You will start by cutting a small section of the crown moulding for measurement. Draw a straight line on a table or piece of paper to represent a wall. 

Once you’ve drawn your “wall”, you can measure how far out the top of the crown moulding reaches. When making calculations, there will typically be two angles that require measurement. 

The first number will represent the crown moulding's top angle, and the second one is the bottom angle. While you can measure both angles with a digital angle finder or protractor, a simple method helps determine the angles. Place a piece of crown moulding into the crotch of a framing square. 

To find which spring angles the crown moulding has, you will check where the ends meet. If both moulding ends have the same measurement, this means the crown moulding has a 45/45 spring angle. When you see the numbers are different, the piece has a 52/38 spring angle. 

Why is a Crown moulding’s Spring Angle Important? 

Now that you know about measuring the crown moulding spring angle, you should know why it’s important. When making cuts, you will need to adjust the miter saw to account for the spring angle for inside corners. Since the most common corner is a 90° cut, you will need to adjust the miter and bevel based on the spring angle. 

If you want to make a 90° cut, you will adjust the compound miter saw accordingly. For a 52/38 angle, you will set the miter at 31.6° and the bevel at 33.9° for a perfect cut. If you have a 45/45 type, you should adjust the miter to 35.3° and set the bevel at 30.0°. Most modern compound miter saws will include these settings on their guides.

Along with 90° corners, there are also measurements for 135.0° and 157.5° cuts for crown moulding. By verifying the spring angle of the moulding, you can ensure that your cuts are perfect every time. However, you should always measure the angle of the corner you are cutting.

In some cases, the top of the wall will not be a perfect 90° angle, and you will need to adjust the cut. There could be lumps of drywall or tape that affect the angle. To find the correct angle for your crown moulding, you will need a protractor. Once you have the angle from the protractor, you will subtract it by 180° and divide it by two. 

The spring angle is an essential component for any project involving installing crown. So you will have trouble installing your crown moulding correctly without knowing the spring angle. However, once you know the spring angle, you can make accurate cuts and make your installation stress-free.