RB millimeter size to carat weight - reliable chart?

[malish985]

I've looked at several different charts and have found them to be inconsistent. Is there a particular one you would recommend?
Also, if looking at purely measurements what would you say a 8.32 x 8.30mm RB stone be carat wise?
Want to make sure the diamond I'm interested in doesn't measure below its carat weight.
Thanks

 

[ecf8503]

Short answer? It depends.

If a stone is cut too deep it will face up smaller. If it is shallow it will face up larger. What you want is ideal proportions of crown and depth%, as well as crown and pavillion angles. You can't judge the quality of the cut by diameter alone.

 

[marymm]

OP - here's a chart I have bookmarked and find very helpful as a general guideline - http://www.ajediam.com/Sizes-of-Diamonds.html

 

[bunnycat]

ANother thing you can do is check some similar carat weight diamonds on one of the diamond sites (take your pick) and see how diamonds of similar weight are comparing in diameter and cross reference to a chart to see if it's all coming together.