Oval Cut Diamond Size Chart (MM)
TheOval cut diamondvaries in length-to-width ratios like the Emerald cut diamond. The chart below compiles average conversions for the millimeter measurements and carat weight of oval cut diamonds.
| 5x3 mm. | 0.25 ct. |
| 6x4 mm. | 0.50 ct. |
| 7x5 mm. | 0.75 ct. |
| 7.7x5.7 mm. | 1.00 ct. |
| 8x6 mm. | 1.25 ct. |
| 8.5x6.5 mm. | 1.50 ct. |
| 9x6.5 mm. | 1.75 ct. |
| 9x7 mm. | 2.00 ct. |
| 10x8 mm. | 2.50 ct. |
| 12x8 mm. | 3.00 ct. |
| 12x8.5 mm. | 3.50 ct. |
| 12.5x8.5 mm. | 4.00 ct. |
| 12.75x8.5 mm. | 4.50 ct. |
| 12x10 mm. | 5.00 ct. |
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Diamond Size FAQs
How is diamond size measured?
Diamond size is measured by carat weight, a unit equal to 0.2 grams. However, size is more accurately and indeed defined by its dimensions, such as length, width, and depth in millimeters. A diamond's diameter (top of the diamond) can indicate its apparent size (especially when comparing two like diamonds).
Is carat the only factor that affects the size appearance of a diamond?
No, other factors such as cut, shape, and setting can affect a diamond's size. A well-cut diamond can appear more significant than its actual carat weight suggests, while a poorly cut diamond may look more petite.
Does the shape of a diamond influence how big it looks?
Yes, some shapes like the oval, marquise, and pear can appear larger per carat than more compact shapes like round or princess cuts. This is due to the elongated shape and larger surface area.
Can the setting make a diamond look bigger?
Halo diamond settings surrounding the center diamond with smaller diamonds can make the central stone appear more prominent. Bezel and prong settings can also affect how the diamond's size is perceived. Lastly, setting a diamond in a petite or skinny band can help make your diamond appear larger.
What's the difference between "carat weight" and "total carat weight"?
Carat weight refers to the weight of a single diamond, while total carat weight (TCW) includes the combined weight of all the diamonds in a piece of jewelry, such as a ring with a center diamond and side stones.
How does diamond size affect price?
Generally, the price of a diamond increases exponentially with its size, assuming that all other quality factors (cut, color, and clarity) remain constant. Larger diamonds are rarer and, therefore, more expensive.
Can two diamonds of the same carat weight appear different in size?
Yes, cut quality and shape can make two diamonds of the same carat weight look different in size. A deep-cut diamond may carry more weight "hidden" in the depth, making it look smaller when viewed from above.
Is it better to get a slightly smaller diamond with higher quality or a bigger diamond with lower quality?
This largely depends on personal preference. Some people prioritize size and are willing to compromise on quality, while others prefer a smaller, high-quality diamond with better brilliance and fire. Finding the right balance that suits your taste and budget is essential.
How can I accurately gauge the size of a diamond when shopping online?
It's crucial to look at the dimensions (length, width, depth) provided and not just the carat weight. Many websites offer actual size views or size comparison tools. Additionally, consider asking for images or videos that show the diamond next to an everyday object for scale.
Are there ethical considerations to keep in mind when choosing a diamond size?
Large diamonds are more likely to be scrutinized for ethical sourcing due to their higher value. Make sure to inquire about the origin of the diamond and whether it is conflict-free. Some people opt for lab-grown diamonds as a more ethical choice, especially for larger stones.
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