Carat Weight Formulas

Knowing a Diamond's Carat weight is of paramount importance when working with these precious stones. This information may prove invaluable in a variety of situations such as when purchasing mounted or antique diamonds or when a precision scale is unavailable to hand. So how do you identify a diamonds approximate carat if there are not other possible ways on hand? 

Our expert Gemmologists at Cairn Diamonds with their years of experience have told us their secrets, which we are happy to share with you- Formulas.

Round Diamonds

 Average Diameter x Average Diameter x the Depth x 0.0061 =  Approximate carat weight. To determine the average diameter of a diamond add the length plus the width and divide it by two.

For example- 7.56mm x 7.58mm x 4.2mm (Depth) x 0.0061 = 1.46ct The Approximate Carat weight. 

Ovals Diamonds

Average Diameter x Average Diameter x depth x 0.0062 = Approximate carat weight. 

For Example - 

Emerald Cut