MM to Carat Conversion
We will go over MM to Carat Conversion. As alternative gemstones, such as moissanite, continue to grow in popularity for engagement rings, many customers frequently ask how gemstone sizes compare to diamonds. In order to clarify the difference, BVW Jewelers has thoughtfully created a helpful guide aimed at converting millimeter (MM) measurements to carat weight. Consequently, this guide simplifies the process, ensuring customers can make well-informed decisions when selecting their perfect gemstone. When looking for that perfect engagement ring. To a 1 carat to a 3 carat diamond ring. Use our friendley carat to mm conversion chart.
How Is Diamond Size Measured MM to Carat Conversion?
Diamonds are typically measured in carats; however, carat refers to weight rather than size. Although carat weight affects how large a diamond appears, two diamonds with identical carat weights can nevertheless look different depending on their cut. For instance, elongated shapes, such as ovals and marquise diamonds, often appear larger than round diamonds of the same weight because of their spread.
Moreover, cut quality further influences a diamond's appearance. In fact, a poorly cut 1.25-carat round diamond might, in contrast, look the same size as a well-cut 1-carat diamond since excess weight is often hidden below the girdle—the widest part of the diamond.
To clarify carat weight further, consider it similar to currency. Specifically, one carat equals 200 milligrams or 0.2 grams and is divided into 100 points. Consequently, a 1.25-carat diamond equals one carat and 25 points, just as $1.25 represents one dollar and 25 cents.
Gemstone Weight vs. Size
Although some jewelers measure all gems in carats, BVW Jewelers, on the other hand, prefers to use millimeter dimensions for non-diamond gemstones. This is primarily because gemstones vary in density, thereby making carat weight less reliable when comparing size.
Similarly, denser gemstones, such as rubies, sapphires, and garnets, typically appear smaller than diamonds of the same carat weight. Conversely, lighter gemstones, including moissanite, topaz, emerald, tourmaline, and aquamarine, tend to look larger.
For instance, a 1.5-carat ruby generally appears smaller than a 1.5-carat diamond due to its higher density. As a result of these variations, MM to carat conversion remains an approximation rather than an exact science.
MM to Carat Conversion Charts
Below are approximate MM to carat conversions for popular diamond and gemstone shapes.
Round Diamonds and Gemstones
| MM Size | Carat Weight |
|---|---|
| 4mm | 0.25 ct. |
| 5mm | 0.5 ct. |
| 6.5mm | 1 ct. |
| 8mm | 2 ct. |
| 9mm | 2.75 ct. |
| 10mm | 3.87 ct. |
| 11mm | 4.91 ct. |
Oval Diamonds and Gemstones
| MM Size | Carat Weight |
| 6x5mm | 0.61 ct. |
| 8x6mm | 1.25 ct. |
| 9x7mm | 2 ct. |
| 10x8mm | 2.5 ct. |
| 12x10mm | 5.05 ct. |
Emerald Cut Diamonds and Gemstones
| MM Size | Carat Weight |
| 7x5mm | 1 ct. |
| 8x6mm | 1.75 ct. |
| 9x7mm | 2.5 ct. |
| 11x9mm | 5.21 ct. |
Princess Cut Diamonds and Gemstones
| MM Size | Carat Weight |
| 5.5mm | 1 ct. |
| 6.5mm | 1.5 ct. |
| 7.5mm | 2.5 ct. |
| 9mm | 4.12 ct. |
Pear Diamonds and Gemstones
| MM Size | Carat Weight |
| 7x5mm | 0.75 ct. |
| 8x6mm | 1.25 ct. |
| 9x7mm | 2 ct. |
| 12x8mm | 3 ct. |
Cushion Cut Diamonds and Gemstones
| MM Size | Carat Weight |
| 5.5mm | 1 ct. |
| 7mm | 2 ct. |
| 9mm | 4.12 ct. |
| 11mm | 7.44 ct. |
Marquise Diamonds and Gemstones
| MM Size | Carat Weight |
| 8x4mm | 0.5 ct. |
| 10x5mm | 1 ct. |
| 13x6.5mm | 2 ct. |
| 15x7mm | 3 ct. |
Asscher Cut Diamonds and Gemstones
| MM Size | Carat Weight |
| 5.5mm | 1 ct. |
| 7mm | 2 ct. |
| 9mm | 4.12 ct. |
| 10mm | 5.62 ct. |
Radiant Cut Diamonds and Gemstones
| MM Size | Carat Weight |
| 6x4mm | 0.5 ct. |
| 8x6mm | 2 ct. |
| 10x7mm | 3.31 ct. |
| 11x9mm | 5.05 ct. |
Heart Diamonds and Gemstones
| MM Size | Carat Weight |
| 5mm | 0.5 ct. |
| 6.5mm | 1 ct. |
| 8mm | 2 ct. |
| 8.5mm | 2.5 ct. |
Frequently Asked Questions
How many MM is 1 carat?
When it comes to round and square diamonds, 1 carat typically measures between 5.5mm and 6.5mm. However, for elongated shapes, 1 carat can instead range from 7x5mm to 10x5mm.
How many MM is 2 carats?
Similarly, two-carat round or square diamonds generally measure between 7mm and 8mm. In contrast, fancy shapes often range from 8x6mm to 9x7mm, whereas marquise diamonds can measure up to 13x6.5mm.
How many MM is 3 carats?
Likewise, three-carat round or square diamonds usually measure between 8mm and 9.25mm. On the other hand, fancy shapes frequently range from 10x8mm to 12x8mm.
Final Thoughts
Ultimately, understanding MM to carat conversions allows you to make an informed decision when choosing the perfect gemstone size for your jewelry. As a result, you can better visualize how different carat weights translate into actual size, ensuring your selection aligns with your style and preferences. Lear more about conversions and more to better understand what you're buying.
Moreover, BVW Jewelers’ specialists are always available to assist with detailed size comparisons and personalized visual guides. Whether you decide to visit our store, book a virtual appointment, or even chat with us online, our expert team remains ready to provide the guidance you need. Therefore, you can feel confident in your choice, knowing you’ve received professional support every step of the way.
