Carat Conversion Chart You read that a stone is .33 carats or 1.5 carats.  What size is a carat?  As you may know a carat is a measure of weight.  10 points make up one carat.  What relationship does weight have on size?  How large is a .75 carat diamond for example?  The exact size depends of the shape of the cut stone.  The following chart will help you to understand how large a stone is by revealing it size by its cut.

Millimeter (mm) to Carat (ct) Gemstone Conversion Chart Carat Size Round/Square Brilliant/Princess Pear Marquise Oval Emerald Heart Trillion 0.25 4.1 6 x 3 5 x 3 5 x 3 4 x 4 4.5 x 4.5 x 4.5 0.50 5.2 6 x 4 8 x 4 6 x 4 6 x 4 5 x 5 6 x 6 x 6 0.75 5.8 7 x 5 9 x 4.5 6.5 x 4.5 6 x 6 1.00 6.5 8 x 5 10 x 5 7 x 5 7 x 5 6.5 x 6.5 1.25 7.0 7.5 x 5.5 1.50 7.4 9 x 6 11 x 5.5 8 x 6 8 x 6 7 x 7 7 x 7 x 7 2.00 8.2 10 x 7 12 x 6 8.5 x 6.5 8.5 x 6.5 8 x 8 8 x 8 x 8 2.50 8.8 12 x 7 13 x 6.5 9 x 7 9 x 7 8.5 x 8.5 9 x 9 x 9 3.00 9.4 12 x 8 14 x 7 10 x 8 10 x 8 9 x 9 10 x 10 x 10 3.50 10.0 13 x 8 14 x 7.5 10 x 8.5 9.5 x 9.5   4.00 10.04 14 x 8 16 x 8 11 x 9 11 x 9 10 x 10 4.50 10.80 14.5 x 9 11 x 9.5 10.5 x 10.5 5.00 11.20 15 x 9 16 x 8.5 12 x 10 12 x 10 11 x 11