Carat is one of the prominent of the four C’s of diamond buying it being the global standard for the weight of a diamond. If you are having problems with visualizing actual diamond sizes in real life, you’ve come to the right place. We have compiled diamond weight charts for the most popular diamond shapes in the market!
A 1 carat (or ct) diamond weighs 0.20 grams. The carat, however is not the size of the diamond. A diamond’s size is measured in millimeters, length by width or the diameter of the diamond.
It takes about 250 tons of rock mining to produce a single 1 carat diamond. That’s 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. The larger the diamond, the rarer and therefore more expensive it is. Diamonds are weighed very precisely, to the nearest 0.01ct.
Diamond carat size comparison
Although each diamond is unique, it is possible to approximate visual size, especially because modern diamonds are cut with machines to ensure precision. Within each carat range, diamonds have an average size in millimeters.
Well-cut round diamonds have less depth than well-cut fancy-shaped diamonds (diamonds other than round). A 1ct round diamond will have ~6.40mm length/width, while a 1ct Princess diamond, which will measure ~5.50mm.
Fancy shapes tend to have more weight and less size. So round-cut diamonds will cost more than fancy shapes of the same carat weight.
Visually, it’s hard to tell the difference between diamonds that vary 5 to 10 percent in carat weight. For example, a 0.95ct and 1ct diamond will be nearly indistinguishable. (Take note if you want a 1ct diamond but don’t want to pay the price for that popular round weight!)
If a diamond is cut too deep, it may look smaller than a lower-carat diamond. When looking at carat weight and millimeter size, it is also important to consider length-to-width ratios for each diamond shape. These will help you understand if a diamond is too shallow or too deep, or if it has desirable proportions. A deep-cut 1ct diamond might look smaller than a 0.95ct shallow-cut diamond.
Diamond Size Chart
Diamonds can be measured in both carat weight and millimeter. While diamonds are purchased based on carat weight — the standard unit of measurement for loose diamonds — it’s important to consider millimeter measurements and ratios to choose the best possible option for your budget.
Round Diamond Size Chart
Currently, the standard 57 facets round brilliant cut is the most popular choice of shape. Due its cutting style that’s optimized for brilliance and dispersion, round brilliants make up for more than 60% of all diamonds sold in the world.
Princess Cut Diamond Size Chart
Princess-cut diamonds are the biggest competition to the round brilliant cut. The perfectly square shape provides a beautiful, sharp alternative to round-cut diamonds, and a princess-cut diamond will cost also considerably less than a round cut. (That’s because more of the rough diamond is used, not wasted, and the price reflects the jeweler’s savings.)
The princess cut diamond’s most variable characteristic based on size is light performance. In any size, a princess cut can have an immaculate sparkle (due in part to the retention of the original rough diamond), but the shine of each facet becomes more brilliant the larger the diamond is.
Oval Diamond Carat Size Chart
The oval cut is a popular choice for women who prefer unique, non-mainstream jewelry. Like emerald-cut diamonds, oval-cut diamonds have an elongated shape and slimming effect on the hand. When an oval-cut diamond is cut to ideal depth proportions, it has a similar brilliance to round-cut diamonds. They brighten as carat size increases.
Cushion Cut Diamond Size Chart
The cushion-cut diamond is a compromise between the round-cut diamond and shapes with sharp corners and edges (princess, rectangle, etc.). The cushion cut is a vintage style, but today it ranks among the five most popular diamond cuts. Cushion cuts are especially prominent in jewelry worn by royalty and celebrities.
With the modernization of the cushion cut, the culets that detracted from the original cushion-cut diamond’s beauty have reduced to unnoticeable ratios, and the facet appearance has grown smaller and more delicate. With increasing size, cushion-cut diamonds show more faceting and clarity.
Marquise Diamond Sizing Chart
The marquise (a.k.a. football-shaped) cut is a popular stone shape in vintage and antique jewelry. It’s another diamond style that looks larger compared to other cuts and shapes. The number of facets in a marquise-cut diamond can change dramatically, depending on size — anywhere from 50 to 60 facets is not uncommon.
Pear Shaped Diamond Size Chart
Pear-cut (or teardrop-shaped) diamonds are comparable to oval-cut diamonds on the uniqueness scale. Although this cut can be used to create one-of-a-kind, nontraditional engagement rings, these diamonds are more commonly used in earrings or solitaire necklaces.
Color is a prominent characteristic of pear-cut diamonds, especially in the rounded bottom part of the stone. The tip loses some of its color in smaller-sized carats, but the bottom and body of the diamond do not.
Emerald Cut Diamond Size Chart
Emerald-cut diamonds resemble rectangle-shaped gems, but like the cushion cut, their corners are softer and more rounded. They’re one of the more popular diamond cuts for vintage-style jewelry and for pairing with real or synthetic emeralds. Because of the elongated shape of emerald-cut diamonds, they sometimes lose a bit of shine, but even a 0.25-carat emerald-cut diamond can easily appear almost twice as big.
Asscher Diamond Carat Size Chart
In the center of all properly cut and finished Asscher-cut diamonds sits a windmill design. This pattern forms as a result of a step cut, similar to that of emerald-cut diamonds. The step cut style doesn’t diminish in smaller-carat Asscher diamonds; the patterns simply become more compact.
Radiant Cut Diamond Size Chart
This cut is a combination of the emerald, round and Asscher cut diamonds. The unique but elegant style goes by many names (usually “emerald” or “rectangle modified” cut), and it makes for one of the most modern stones on the market. Characteristics don’t vary from one carat size of radiant-cut diamond to another; the entire stone just becomes a more compact version of a larger one, adding to its uniqueness.
Heart Shaped Diamond Sizing Chart
Remember: A carat is a weight, so a diamond’s measurement in millimeters can vary depending on how it’s cut. Choose diamonds that are cut very well. Those diamonds tend to have less depth and more spread. This means their measurements are larger, making the diamond look visually larger than its carat weight.
Selecting a Diamond Size
When shopping for a diamond, consider the carat weight, and understand that millimeter size can vary for diamonds of the same carat weight. While diamonds are cut precisely using machinery, slight variations can be caused by inclusions or other natural factors in the diamond. A diamond’s depth can also affect the millimeter size from a face-up view.
If you’re concerned about diamond sizing, remember that you can ask a gemologist about the ideal proportions for that shape. Some diamonds are priced lower than expected because their millimeter size is less than ideal. Be sure to consider diamond size against other factors like clarity and color — it’s counterproductive to make a significant compromise just to get a larger diamond.
Still not sure which color to choose? Feel free to contact us for personal help. Our experts are here to help you with the very best diamonds to choose from.