How To Tell The Size of a Diamond

Size of a diamond is a factor when determining the worth and establishing size. A large diamond is worth more. The size of the diamond will determine the value. They are measured with millimeters, and size can be determined by anyone.

• Lay the diamond on a hard surface. There should be enough room to measure it without worrying about losing a stone.


• Get measuring tape that uses millimeters. Place the end of it at the diamond. Keep the measuring tape steady to get the correct reading.


• Look at the end of the diamond which is the longest length. Determine the length by checking the tape for the measurements in millimeters. You will need to count 1/2 and 1/3 mm to get an accurate reading.


• Use a conversion chart to convert millimeters to carats. If you don’t have a conversion chart, then you can find one online.  Diamonds are sold and measured in carats. A 3mm diamond in diameter is the same as 1/10 of one carat. If the measurement is 6 ½ mm, then the diamond is one carat.


• Take the diamond to an appraiser. People who appraise diamonds are trained and have special tools for determining exact carat size. You want to use an independent appraiser instead of one at a jewelry store. A jewelry store appraiser may have a tendency to exaggerate the carat size, especially when buying from their store. The appraiser should also have a gemologist diploma from a reputable university.