Table and depth are two of the proportion figures on a diamond grading report. The table is the large, flat facet on the top of the stone. Depth is the height from that table down to the culet, usually written as a percentage of the width. Together they describe how the diamond is built, and they are among the first things we read when we look at a report with you. They are not a substitute for seeing the stone.
What the table is
The Gemological Institute of America describes the table as the top horizontal facet of the diamond, and usually the largest. Light enters through it, and some of that light is reflected back to you. On a report for a standard round brilliant, the table is also given as a percentage of the average girdle diameter. That percentage is a useful description, but GIA is clear that it does not consider individual proportions in isolation. In its diamond anatomy guide, GIA notes that a diamond with an Excellent cut grade will have a table size between 52 and 62 percent, while stressing that other proportions matter too.
What depth means
Total depth is the distance from the table to the culet. GIA expresses it as a percentage of the average girdle diameter for a round brilliant, calculated from the millimetre measurements and reported to the nearest tenth of a percent. A stone that is very deep can hide weight below the girdle, so it may look smaller face up than a shallower stone of the same carat. A stone that is very shallow can also leak light. Those effects depend on the rest of the proportions, which is why we do not treat a single depth figure as a pass or fail.
GIA's cut grading system for standard round brilliants considers table, depth, crown and pavilion angles and other measurements together. A depth figure that can still sit within the Excellent range, according to GIA's published estimating material, is 57.5 to 63.0 percent, but a combination near the edges of several ranges can lower the grade. Our guide to why cut matters explains the grade itself.
Fancy shapes and the report
Most fancy shapes do not receive a GIA cut grade in the same way as a standard round brilliant. The report still lists the length, width and depth in millimetres, and it usually includes the depth percentage. We still look at how the stone returns light, because two ovals with a similar depth figure can look quite different. Our guide to the 4Cs sets that wider context.
We work by video consultation and message. We will talk through the report, show you the stone, and agree the setting around it. Nothing is made until you approve the design and the stone in writing. A 70 percent deposit is paid then, making time is 5 to 6 weeks, and the ring is UK hallmarked before insured, tracked FedEx delivery. If you would like to look at a report with us, get in touch, browse the diamonds we can source, or read our guide to how to read a GIA certificate.
Frequently asked questions
What do table and depth mean on a diamond report?
The table is the large, flat facet on the top of the diamond. Depth is the height from that table down to the culet, usually written as a percentage of the width. Both figures are on a standard grading report, and they help to describe the stone's proportions.
Is there a single ideal table or depth percentage?
No. For a standard round brilliant, GIA considers table, depth and other proportions together when it assigns a cut grade, rather than judging any one number on its own. In GIA's published cut material, a table between 52 and 62 percent can still sit within the Excellent range, provided the other proportions work with it.
Do fancy shapes have the same table and depth grades?
Most fancy shapes do not receive a GIA cut grade in the same way a standard round brilliant does. The report still records the millimetre measurements and the percentages, which we review with you alongside a view of the stone.
Should you choose a diamond from the percentages alone?
No. The numbers are a useful starting point, but two stones with similar percentages can still look different in the hand. We look at the report and at the diamond on a video consultation before you approve the stone in writing.