Total depth % is a stupid measurement.

[Nate]

Seems to me that total depth percentage is quite the stupid measurement. Diamonds on PScope give width and height measurements in millimeters already, so depth % is useless! If it were the measurement from the girdle down then we could find the approximate average of the crown and pavillion angles. Is there some legacy to total depth percentage?

 

[dimonbob]

I agree with you Nate. It all started back when almost no one had ever heard about an Ideal cut. The diamond manufacturers wanted only the total depth, not a break down and GIA agreed with them.
The problem now is that GIA-GTL wants to also add cut information like AGS Lab reports but cannot agree on what those numbers are.
So, we are stuck with the same GIA report plus having to get a Sarin report to find out other information that GIA should have given us.
Change is difficult.