Diamond Guide: The Ideal Crown Angle and Pavilion Depth

The crown angle, pavilion depth and angle of a diamond can all make a big difference in the end result of a diamond’s appearance, creating either a sparkling wonder or a dull stone.

The Ideal Crown Angle and Pavilion Depth

In this guide we explain the different angles and depths, as well as how to calculate them. We also provide a handy table with the ideal round cut diamond proportions to help you find the perfect diamond.

Crown Angle

Crown Angle

The top part of the diamond is called the crown, below the flat top table, and ‘crowning’ the pavilion cone. But the actual crown angle of a diamond refers to the degree of separation between the diamond’s girdle and table.

How important is crown angle?

The crown angle plays a major role in a diamond’s face-up appearance. When combined with ideal overall proportions, an ideal crown angle disperses maximum light, also referred to as a diamond’s fire. This makes the crown angle an extremely important aspect in a diamond’s proportions.

Crown Angle
What is the Best Crown Angle for a Diamond?

What is the Best Crown Angle for a Diamond?

The expert opinion is that the best crown angle is between 32-35 degrees. When the crown angle of diamond is smaller than 32 degrees it is called a spread-cut, creating a foggy appearance in the diamond. This is caused by an overly large table area and a too thin girdle, which also causes the edges to be unprotected.

What is the Best Crown Angle for a Diamond?
How to Calculate the Crown Angle of a Diamond

How to Calculate the Crown Angle of a Diamond

  1. Divide the table of the diamond by 100.
  2. Subtract your answer from 1.
  3. Multiply that answer by 50.
  4. Divide the crown depth by said answer above.
  5. Using a scientific calculator, press the Tan – 1 button. The answer given will be the actual crown angle expressed in degrees.

How to Calculate the Crown Angle of a Diamond
Pavilion Depth

Pavilion Depth

The pavilion of a diamond refers to the lower part or the ‘V’ shape of a diamond, it acts as a mirror to reflect light back through the top crown and table to the viewer.

What is the pavilion depth on a diamond?

In its simplest sense, the pavilion depth is the distance from the flat top table to the culet, or bottom point of the cone, of a diamond.

Pavilion Depth
Impact of Pavilion Depth

Impact of Pavilion Depth

Pavilion depth contributes to both fire and brilliance in a diamond, it is also a way to increase the size of a modest diamond’s appearance. A shallower depth helps the diamond appear larger when viewed from above, although if it’s too shallow the diamond will appear dull and muted.

The pavilion depth is expressed as a percentage of average girdle diameter, and it can be judged visually, or measured and calculated.

Impact of Pavilion Depth
How to Calculate the Pavilion Depth Percentage

How to Calculate the Pavilion Depth Percentage

  1. Divide the pavilion depth by the average girdle diameter
  2. Multiply that answer by 100 
  3. The answer will be the pavilion depth percentage.

How to Calculate the Pavilion Depth Percentage
Expert Guidance
Need help? Speak with our Diamond & Jewelry Experts at 866-737-0754 or chat now!
Expert Guidance
Need help? Speak with our Diamond & Jewelry Experts at 866-737-0754 or chat now!
Pavilion Angle

Pavilion Angle

Some people like to use the pavilion angle instead of pavilion depth percentage when they are evaluating a diamond’s proportions. Really, they are just two different ways of looking at the same aspect. The steeper the angle, the greater the depth percentage.

The pavilion angle creates that sparkling, eye-catching appearance revered in diamonds. The angle refracts light from one side of the diamond to another before reflecting outwards, creating a gorgeous prism of light. Diamonds that don’t possess the ideal pavilion angles, if they are perhaps too deep or too shallow, will be sorely lacking in beauty.

Pavilion Angle
How To Calculate The Pavilion Angle of a Diamond

How To Calculate The Pavilion Angle of a Diamond

  1. Determine the pavilion depth of the diamond and enter the answer in a scientific calculator
  2. Then divide the answer by 50
  3. Next, press the Tan – 1 button on your scientific calculator.
  4. The answer will be the actual pavilion angle expressed in degrees.

How To Calculate The Pavilion Angle of a Diamond

Ideal Diamond Proportions for Round Cut Diamonds

Depth Percentage
59% to 62.6%
Pavilion Angle
40.6% to 41%
Table Size Percentage
54% to 57%
Crown Angle
34% to 35%
Girdle Thickness
Thin to Slightly Thick
Culet
None to Pointed

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