Depth percentage is the proportion of the total diamond depth as compared to the total diameter. Depth percentage affects how the light will interact in the diamond, and thus impacts its brilliance. It is calculated by dividing the total depth of the diamond by the total girdle diameter. The total diameter is fixed to 100% as a rule for all diamonds. However while calculating depth percentage the dimensions in millimeter are considered later multiplied by hundred for percentage value.
Depth Percentage Fancy Cut Diamond = depth (in mm)
total width (in mm)
A round brilliant diamond has a different criterion to calculate the depth percentage. Here the total depth is divided by the average girdle diameter. For example, if the average diameter is 6.00 mm and total depth 4.00 mm the depth percentage will be 66.7%.
Depth Percentage Brilliant Cut Round Diamond = depth (in mm)
average girdle diameter (in mm)
The Depth Percentages that are commonly considered best for each shape may vary slightly. As exceptions princess, radiant and emerald cuts, can have 70 - 75% for acceptable depth percentage range. To have better understanding refer to the Depth
Percentage chart below:- |