Diamond Carat Weight

Based on carats, the measure of a diamond's weight, you can't always tell the diamond's size. However, carats affect the way diamonds are priced, and the number changes exponentially. In this piece we've explained the difference 0.1 carats can make.


Diamond Carat Weight

The weight of a diamond is referred to in terms of carats. One carat equals 200 milligrams (0.20 grams) and is divided into 100 points for precision. A diamond weighing one tenth of a carat may be referred to as 0.10 carats or “10-points”.

A diamond’s carat weight is not necessarily reflective of its size. Two diamonds of the same carat weight may appear slightly different in size when viewed from above.

When evaluating the size of a diamond, the top diameter and cut grade must also be taken into account. The distance across the top of the diamond is crucial, as this is how diamonds are generally viewed once set in jewelry. The cut similarly affects perceived size. A well-proportioned diamond maximizes light, making it appear larger.

Diamond prices tend to jump by half-carats. You will find that the price difference between a 0.9 and 1.0 carat diamond is much larger the difference between a 0.8 and 0.9 carat diamond. Furthermore, diamond prices increase exponentially, rather than linearly. The scarcity of large gem-quality rough diamonds means that a single two carat diamond will cost much more than two one carat diamonds.

TIP: “Carat” (abbreviated ct) is not the same as “karat” (abbreviated K or kt). Carat is measure of gemstone weight while karat is a measure of gold purity.