carats are a unit of weight. Millimeters are units of volume. So, the question is unanswerable. It's like asking "how many pounds in a foot?".
16mm = 1,6 cm.
There are 142 carats in an ounce.
2267.96185 carats.
30,000 carats.
7 CARATS
There are roughly 2,267 carats in a pound.
1 ounce is 138.29 carats.
Five carats.
1.6cm
One ounce = about 141.7 carats.
There are 45.52 carats on the hope diamond
5678 carats in 5 millimeters