Open and print this PDF to see the actual size round brilliant diamonds should be for their weight. Printable Proportionate Spread: 1 to 10 Carats Read on to see examples of brightness and visual size-appearance.ĭo you want proper spread and great brightness combined? Check out the diamond brands offered by our exceptional vetted vendors, like James Allen True Hearts ™, Whiteflash A CUT ABOVE ®, and Astor by Blue Nile ™ Diamond Carat Chartīe sure any round brilliant diamond you are considering has proportionate spread for its carat weight: A diamond’s spread is the average of the first two measurements in millimeters (length and width).Ĭarat Weight and Size: Under 1.00 Carat Carat Weight While the shallow diamond above will appear physically larger from above in jewelry store spotlights it’s not necessarily the best choice for those seeking the diamond which will appear the brightest and largest through multiple illumination environments. Diamonds cut too deep often suffer from brightness reduction, and these diamonds are very common in the marketplace. It weighs 1.00 carat and measures 6.24-6.26 x 4.06 mm, making its spread 6.25 mm. The right example is like the meatball in the first illustration.It weighs 1.00 carat and measures 6.44-6.46 x 3.80 mm, making its spread 6.45 mm. Diamonds cut too shallow may suffer from brightness reduction in close viewing. The average of the first two numbers (length and width) are its spread, which is 6.65 mm. It weighs 1.00 carat but measures 6.64-6.66 x 3.80 millimeters. The shallow example is like the pancake in the first illustration.A diamond’s grading report will include its external measurements in millimeters, from which you can determine its spread, side to side. This is why it’s important to correlate diamond carat weight with side-to-side spread in millimeters, to ensure a diamond “faces-up” the correct size for its weight. Same weight but different physical spread But they look different on the tray, because the meatball’s has a deep vertical geometry while the pancake is distributed horizontally. Imagine a 1 pound meatball and a 1 pound pancake. Why? Because we usually view diamonds from only one direction – looking down from above. A carat can also be divided into 100 points, so jewelers call a 1/4 carat diamond a 25-point diamond, a 1/2 carat diamond a 50-pointer, and so on. Putting that in perspective, a small paperclip weighs about 600 milligrams, so a paper clip on your finger weighs about the same as a three carat diamond. Ask our PriceScope members and industry experts for a second opinion or get lost in the thousands of user-shared diamond and jewelry images for inspiration.