Total Depth Percentage
Total Depth / Total Diameter = Total Depth Percentage
Calculated by dividing the diameter of the diamond by the measurement from table to cutlet. This measurement will always found on a GIA certified diamonds instead of the crown angle, pavilion depth percentage, or pavilion angle.
In 1919, Marcel Tolkowsky examined the relationship between a diamond cut and the reflection and refraction of light passing through a diamond. He determined, based on his studies, what would be the ideal proportions to cut a round brilliant shaped diamond to create the optimum brilliance. Today, His design is known as the “American Ideal Cut.
In 1955, AGS established their own “AGS Ideal Cut” , which included limited ranges for table size, crown angle, pavilion depth, cutlet size and girdle thickness as shown in the diagram below. Today, the “AGS Ideal Cut” diamond is a highly popular choice.