Diamond carat weight formula

Round diamonds formula:
diameter x diameter x depth x .0061 = diamond carat weight

Marquise diamonds:
length minus 1/3 width x width x depth x .0077 

Emerald cut diamonds, Squares or baguettes :
length minus 1/3 width x width x depth x .013 

Pear Shape diamonds:
length x width x depth x .0062 

Diamond Size in mm

Diamond size chart - in addition to the diamond size chart of mm to diamond carat weight we have included a actual diamond carat size chart/picture 

Actual diamond size

Diamond carat size

Actual diamond size pictures