Depth and Table Percentages   To calculate the table and depth percentages of a Round Billiant Cut diamond, use the following formula: Table %  =  Table Measurement (mm)                                        Average Girdle Diameter/Width (mm) Depth % =  Depth (mm)                                       Average Girdle Diameter/Width (mm) Table of Contents Encyclopedia Home Introduction The 4 C's Terminology Depth and Table Percentages How to use The Diamond Buying Guide GIA, AGS, & Commercial Grade Conversion Charts Round Brilliant , Brilliant, Old Mine Cut Pear and Oval Cuts Marquise Cut Heart Shape Princess and Radiant Cuts Emerald, Cushion, and Carre Cut Trillions     For fancy cut diamonds the following calculations are made: Table %  =  Table Measurement (mm)                                        Width (mm) Depth % =  Depth (mm)                    Width (mm)