Diamond Carat is the most visual of the 4 C’s of diamonds. Carat is a weight measure for a diamond that is globally recognized. Not to be confused with karat (a measure of gold purity), a 1.00 carat or ct diamond weighs 0.20 grams. Contrary to popular belief, the carat is not the size of the diamond. The size of a diamond is measured in millimeters by length and width or in other words the diameter of the diamond. It typically takes about 250 tons of rock mining to produce just 1.00ct of diamond. That is why diamonds are rare and expensive. Diamonds come in a variety of shapes and carat weights. A diamond cutter’s highest priority is to maximize carat weight of a diamond. The larger the diamond, the rarer and therefore more expensive it is. Diamonds are weighed with carat/gram scales very precisely to the 0.01ct. This measurement for diamond weight is universal and is used by countries around the world. It is also apoint of reference in when lookin at the certificate of any diamond regardless of which institution certifies the diamond.
Carat Price Effect
Diamond pricing increases exponentially, not linearly, as diamond carat weight increases. Once a diamond hits it’s critical weight, the price bumps up. The critical weights are: 0.30ct, 0.40ct, 0.50ct, 0.70ct, 0.90ct 1.00ct, 1.50ct, 2.00ct, 3.00ct, 4.00ct, 5.00ct, 10.00ct. Diamond cutters will do everything they can to keep the diamond weight at or above each critical weight. Therefore, while it is often recommended to purchase 0.95ct diamonds vs. 1.00ct diamonds, it’s very difficult to find 0.95ct diamonds. Additionally, diamond manufacturers and suppliers know this “trick” and so they’ll price their diamonds accordingly.
The average diamond carat weight is 0.90ct. Consumers prefer Carat above the other C’s of diamonds because carat is the most visual C. When pricing diamonds, think about carat on one side and the other 3 C’s on the other side. In order to fit your diamond budget, as you increase carat, you may need to reduce the other C’s. Vice versa, if you increase the other C’s, you may need to decrease carat. Visually, a larger carat size will fill up more of the hand. However, if you do not maximize for cut and clarity, the reflection of light within the diamond will be hindered. This means that although you may get carat size, you will not get the sparkle from the diamond. Therefore, it is important to have a balance of all the 4 C's even if you are optimizing for carat weight for your engagement ring diamond.
Please see our diamond price estimator to understand the approximate pricing across a variety of diamond sizes, when combined with the other diamond attributes. Below you can also see different diamond carat sizes on hand to get an idea of the visual appearance of diamonds when worn within an engagement ring. This representation uses an average hand size to show the diamond carat weight. When shopping, be sure to consider her hand size as well as her finger size. These are important factors in determining which carat size you should be aiming for and which ring style to pair your diamond with. While the illustrations show a round diamond, keep in mind that most fancy diamond shapes like emerald, oval and pear will look larger on hand than a round diamond of the same carat weight. Learn more about the various diamond shapes to understand which is the best fit for her ring. Finally, also consider that once set within a ring, the diamond carat weight can look even larger depending on the engagement ring style that is chosen.