Enter all but one of the length, width, and depth of the diamond into the calculator to determine the diamond size.

Diamond Size Formula

The following formula is used to calculate the diamond size:

 DS = (A * D * C) / (B * E)


  • DS is the diamond size
  • A is the length of the diamond
  • D is the width of the diamond
  • C is the depth of the diamond
  • B is a constant factor
  • E is a constant factor

To calculate the diamond size, multiply the length, width, and depth of the diamond. Then divide the result by the product of the constant factors B and E.

What is a Diamond Size?

Diamond size refers to the physical dimensions or weight of a diamond, typically measured in carats. One carat is equivalent to 200 milligrams. The size of a diamond is one of the most significant factors that determine its value, along with its cut, color, and clarity, collectively known as the 4Cs. However, size does not always equate to quality. A larger diamond may have poor color, cut, or clarity, making it less valuable than a smaller diamond with excellent ratings in these areas. The size of a diamond can also influence its brilliance and sparkle. Larger diamonds have a larger surface area, allowing for more facets to reflect light. However, if the diamond is cut poorly, it may not reflect light as well, reducing its brilliance.

How to Calculate Diamond Size?

The following steps outline how to calculate the Diamond Size.

  1. First, determine the length of the diamond (in millimeters).
  2. Next, determine the width of the diamond (in millimeters).
  3. Next, determine the depth of the diamond (in millimeters).
  4. Next, gather the formula from above = Diamond Size = (Length x Width x Depth) / 200.
  5. Finally, calculate the Diamond Size.
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

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

Length (mm) = 5

Width (mm) = 3

Depth (mm) = 2