January 28th 2022
Radiant Cut Diamond Size Chart
By Devin Jones
Chart of diamond sizes showing the relationship between carat size, diameter, and surface area for radiant cut diamonds.
Radiant Cut Diamond Carat Size Chart
|Radiant Carat||Radiant Surface Area (sq. mm)|
Radiant Carat Size vs. Surface Area
The above diamond size chart shows the changing dynamic between an increase in carat size and the respective increase in a radiant cut diamond's visual appearance as measured by surface area. While carat weight is typically thought of as the best indication of a diamond's size (meaning visual appearance), carat is actually a measure of weight. Diamonds of the same carat size can vary slightly in their visual appearance depending on how they are cut. For instance, a diamond with a deeper cut will appear smaller than a diamond of the same carat weight with a shallower cut.
For our radiant cut diamond analysis we averaged the diameters of hundreds of thousands to come up with a simple exponential function (shown on the chart below). Using this formula we can study the corresponding changes in diameter and surface area for a given change in carat weight. Interestingly, as the carat size increases we notice a significant slowing of the surface area. This is because carat weight scales as a measure of volume (mm cube) while surface area scales at a slower rate (mm squared).