The 4 C’s of the Diamond: Carats

Carat (Ct.) is the unit of measurement that determines the weight of the diamond, not the size. Commonly people have the idea that the greater the weight the diamond has a larger size when in reality this is not always the case. Diamonds are cut in different ways to shape different designs that can generate the perception that a diamond may be larger or smaller.

The word "carat" or Carat in its English definition, comes from "carob" (a seed), which is the unit of measurement used by diamond merchants. The current weight of one carat equals 0.2 grams. It is important to mention that the karat of diamonds corresponds to weight and does not have any kind of relationship with the karat of gold that corresponds to purity.

Also remember that two diamonds of the same carat weight can have very different costs depending on other factors (such as cut, color and clarity).

Differences in diamonds

A deeply cut diamond has a greater proportion of its total weight "hidden" in the depth, resulting in a smaller diameter than a well cut diamond. These differences are usually small, but noticeable.

Even when comparing two diamonds with exactly the same carat, it can give the impression that one is larger than the other.

It is also possible to have a larger diamond (by design, brilliance, cut) and with less weight, than one that is smaller. (For example, a .98 cts diamond that looks larger than a 1.00 cts diamond). If the diamond is deep cut, the brilliant will appear smaller.

A well-cut diamond may even have a slightly less carat weight than a deeply cut diamond, yet still have a larger diameter, making it appear larger in size.

In the following table, you can find an example of the visual difference between the most common weights:

Most of the time, you can easily perceive a difference in size between every 0.25cts points between one diamond and another. The average measurements of the most popular round diamonds are among those described in the following table:


Measurement (Diameter)

.25 cts

4.1 mm

.50 cts

5.0 mm

1.00 cts

6.4 mm

1.50 cts

7.3 mm

2.00 cts

8.1 mm

2.50 cts

8.5 mm

3.00 cts

9.4 mm

Tips for buying the ideal diamond

Dídimanat recommends considering the following factors when evaluating purchasing a high carat diamond: Budget, ring design.

  • If you are budget conscious, you can start with low carat diamonds, for example you can find a big difference in price between a 1.00 cts diamond and a .90 cts diamond. They may even look the same when it comes to size, but that slight change in weight can make a big difference to the final price.

  • If you already know the ring design you want for her, please note that some settings are specially made for some diamonds and specific measurements, otherwise the ring may dull the appearance of the diamond.

Remember that each diamond shape also has its own benefits, for more information, do not hesitate to contact our experts! We can help you answering your questions and provide you with the best advice to help you find the ideal diamond!