The Importance of a Diamond’s Millimeter Measurement
The millimeter measurement of a diamond reveals its true size. Diamonds of the same carat weight can appear different in size depending on faceting. For a diamond that looks larger faceup, consider fancy shapes like emerald, oval, and pear, as they often appear bigger compared to round diamonds.
If you are choosing a diamond for an existing ring setting, you will need to consider millimeter measurements. Different setting styles may require specific millimeter sizes.
Especially for non-round shapes like cushion and emerald, millimeter measurements are vital. They indicate if a cushion diamond is squarish and if an emerald diamond is more rectangular.
(Refer to our diamond sizing charts below for carat weights of well-cut diamonds.)
When diamond shopping, both the carat weight and millimeter measurements can be found on the diamond’s certificate. At Artful Bracelets, we provide GIA certificates for natural diamonds and IGI certificates for lab-grown diamonds.
Understanding “Pointers”
In trade and wholesale terms, pointers refer to specific millimeter sizes and carat weights. For instance, a one-pointer is a 0.01 carat diamond and a two-pointer is a 0.02 carat stone, and so forth. These terms are commonly used to describe smaller accents in diamond engagement rings or jewelry. It’s important to educate yourself on average millimeter sizes of different carat weights to find the best option.
Round Diamond Size Chart
The round brilliant diamond is highly popular for engagement rings due to its versatility and aesthetic appeal. Ideally cut and finished with 57 facets, it can outshine most other diamonds. A round diamond’s size affects the stone’s color saturation, clarity, and light performance.
| MM Size | Carat Weight |
|---|---|
| 0.8 mm. | 0.0025 ct. |
| 1 mm. | 0.005 ct. |
| 1.15 mm. | 0.0067 ct. |
| 1.12 mm. | 0.0075 ct. |
| 1.25 mm. | 0.01 ct. |
| 1.3 mm. | 0.01 ct. |
| 1.5 mm. | 0.015 ct. |
| 1.75 mm. | 0.02 ct. |
| 1.8 mm. | 0.025 ct. |
| 2 mm. | 0.03 ct. |
| 2.25 mm. | 0.04 ct. |
| 2.5 mm. | 0.06 ct. |
| 2.75 mm. | 0.08 ct. |
| 3 mm. | 0.11 ct. |
| 3.25 mm. | 0.14 ct. |
| 3.5 mm. | 0.17 ct. |
| 3.75 mm. | 0.21 ct. |
| 4 mm. | 0.25 ct. |
| 4.25 mm. | 0.28 ct. |
| 4.5 mm. | 0.36 ct. |
| 4.75 mm. | 0.44 ct. |
| 5.0 mm. | 0.50 ct. |
| 5.25 mm. | 0.56 ct. |
| 5.5 mm. | 0.66 ct. |
| 5.75 mm. | 0.75 ct. |
| 6 mm. | 0.84 ct. |
| 6.25 mm. | 0.93 ct. |
| 6.5 mm. | 1.00 ct. |
| 6.8 mm. | 1.25 ct. |
| MM Size | Carat Weight |
|---|---|
| 7 mm. | 1.30 ct. |
| 7.3 mm. | 1.50 ct. |
| 7.5 mm. | 1.67 ct. |
| 7.75 mm. | 1.75 ct. |
| 8 mm. | 2.00 ct. |
| 8.25 mm. | 2.11 ct. |
| 8.5 mm. | 2.43 ct. |
| 8.7 mm. | 2.50 ct. |
| 9 mm. | 2.75 ct. |
| 9.1 mm. | 3.00 ct. |
| 9.5 mm. | 3.35 ct. |
| 9.75 mm. | 3.61 ct. |
| 10 mm. | 3.87 ct. |
| 10.25 mm. | 4.16 ct. |
| 10.5 mm. | 4.41 ct. |
| 10.75 mm. | 4.57 ct. |
| 11 mm. | 4.91 ct. |
| 11.25 mm. | 5.49 ct. |
| 11.5 mm. | 5.85 ct. |
| 12 mm. | 6.84 ct. |
| 12.25 mm. | 7.26 ct. |
| 12.5 mm. | 7.36 ct. |
| 12.75 mm. | 7.52 ct. |
| 13 mm. | 8.51 ct. |
| 13.5 mm. | 9.53 ct. |
| 14 mm. | 10.49 ct. |
| 15 mm. | 12.89 ct. |
| 16 mm. | 16.06 ct. |
| 17 mm. | 18.00 ct. |
Princess Diamond Size Chart
Princess-cut diamonds are the main rival to round brilliant-cut diamonds. With their distinct squared shape, princess cuts offer an attractive and sharp alternative, often costing significantly less than their round counterparts. This price difference is due to better utilization of the rough diamond, leading to reduced wastage and greater savings for jewelers, which is then reflected in the price.
The light performance of princess-cut diamonds varies greatly depending on the size, but they can exhibit remarkable sparkle across all dimensions. This is partly because more of the original rough diamond is retained, enhancing each facet’s shine as the diamond size increases.
| MM Size | Carat Weight |
|---|---|
| 1.5 mm. | 0.015 ct. |
| 1.75 mm. | 0.03 ct. |
| 2.00 mm. | 0.06 ct. |
| 2.25 mm. | 0.08 ct. |
| 2.50 mm. | 0.10 ct. |
| 2.75 mm. | 0.13 ct. |
| 3.00 mm. | 0.18 ct. |
| 3.25 mm. | 0.26 ct. |
| 3.50 mm. | 0.29 ct. |
| 3.75 mm. | 0.31 ct. |
| 4.00 mm. | 0.39 ct. |
| 4.25 mm. | 0.44 ct. |
| 4.50 mm. | 0.50 ct. |
| 4.75 mm. | 0.64 ct. |
| 5.00 mm. | 0.75 ct. |
| 5.25 mm. | 0.75 ct. |
| 5.50 mm. | 1.00 ct. |
| 5.75 mm. | 1.11 ct. |
| 6.00 mm. | 1.25 ct. |
| 6.25 mm. | 1.39 ct. |
| 6.5 mm. | 1.50 ct. |
| 6.75 mm. | 1.75 ct. |
| 7 mm. | 2.00 ct. |
Cushion Diamond Size Chart
The cushion-cut diamond finds a middle ground between round-cut diamonds and those with sharp edges like princess or rectangular cuts. Although it’s a vintage design, it remains among the top five choices today, particularly favored among royals and celebrities.
With modern updates to the cushion cut, the previously noticeable culets are now significantly reduced, enhancing the diamond’s beauty. Additionally, the facets have become smaller and more intricate, providing greater clarity and enhanced sparkling effects as the diamond size increases.
| MM Size | Carat Weight |
|---|---|
| 4.2 mm. | 0.40 ct. |
| 4.9 mm. | 0.50 ct. |
| 5.25 mm. | 0.75 ct. |
| 5.5 mm. | 1.00 ct. |
| 6 mm. | 1.25 ct. |
| 6.5 mm. | 1.50 ct. |
| 7 mm. | 2.00 ct. |
| 7.5 mm. | 2.50 ct. |
| 8 mm. | 3.00 ct. |
| 8.5 mm. | 3.50 ct. |
| 9 mm. | 4.12 ct. |
| 9.5 mm. | 5.09 ct. |
| 10 mm. | 5.62 ct. |
| 11 mm. | 7.44 ct. |
| 12 mm. | 9.52 ct. |
| 13 mm. | 12.66 ct. |
Emerald Diamond Size Chart
Emerald-cut diamonds, recognized for their rectangular shape with softened corners, are a popular choice for vintage-style jewelry and often paired with real or synthetic emeralds.
Although diamonds sometimes lose a bit of their shine, even a 0.25-carat emerald-cut diamond can appear nearly twice its actual size.
| MM Size | Carat Weight |
|---|---|
| 3×2 mm. | 0.10 ct. |
| 3.5×2 mm. | 0.12 ct. |
| 4×2 mm. | 0.15 ct. |
| 4×3 mm. | 0.20 ct. |
| 5×3 mm. | 0.29 ct. |
| 5.5×3.5 mm. | 0.46 ct. |
| 6×4 mm. | 0.50 ct. |
| 6.5×4.5 mm. | 0.75 ct. |
| 6.5×4.5 mm. | 0.88 ct. |
| 7×5 mm. | 1.00 ct. |
| 7.3×5.3 mm. | 1.25 ct. |
| 7.5×5.5 mm. | 1.50 ct. |
| 8×6 mm. | 1.75 ct. |
| 8.5×6.5 mm. | 2.00 ct. |
| MM Size | Carat Weight |
|---|---|
| 9×7 mm. | 2.50 ct. |
| 10×7.5 mm. | 3.00 ct. |
| 9.5×7.5 mm. | 3.21 ct. |
| 10×8 mm. | 3.79 ct. |
| 11×9 mm. | 5.21 ct. |
| 12×8 mm. | 5.34 ct. |
| 12×10 mm. | 6.00 ct. |
| 14×8 mm. | 6.25 ct. |
| 13×9 mm. | 6.38 ct. |
| 14×10 mm. | 8.48 ct. |
| 13×11 mm. | 9.13 ct. |
| 14×12 mm. | 11.26 ct. |
| 16×12 mm. | 14.22 ct. |
| 17×13 mm. | 16.50 ct. |
Oval Diamond Size Chart
The oval cut is favored by women who enjoy unique, non-traditional jewelry pieces. Similar to emerald-cut diamonds, oval-cut diamonds possess an elongated shape, creating a slimming effect on the hand. When perfected to ideal depth proportions, an oval-cut diamond can shine almost as brilliantly as a round-cut diamond, with increasing brilliance as the carat size grows.
| MM Size | Carat Weight |
|---|---|
| 4.5×3.5 mm. | 0.21 ct. |
| 5×3 mm. | 0.21 ct. |
| 5.5×3.5 mm. | 0.33 ct. |
| 5×4 mm. | 0.35 ct. |
| 6×4 mm. | 0.50 ct. |
| 6×5 mm. | 0.61 ct. |
| 6.5×4.5 mm. | 0.65 ct. |
| 7×5 mm. | 0.75 ct. |
| 7.7×5.7 mm. | 1.00 ct. |
| 8×6 mm. | 1.25 ct. |
| 9×6 mm. | 1.41 ct. |
| 8.5×6.5 mm. | 1.50 ct. |
| 9×7 mm. | 2.00 ct. |
| MM Size | Carat Weight |
|---|---|
| 10×8 mm. | 2.50 ct. |
| 10.5×8.5 mm. | 2.88 ct. |
| 12×8 mm. | 3.00 ct. |
| 11×9 mm. | 3.85 ct. |
| 12×10 mm. | 5.05 ct. |
| 14×10 mm. | 5.81 ct. |
| 13×11 mm. | 6.05 ct. |
| 14×12 mm. | 8.21 ct. |
| 15×12 mm. | 8.76 ct. |
| 16×12 mm. | 9.32 ct. |
| 16×14 mm. | 11.88 ct. |
| 18×13 mm. | 12.86 ct. |
| 20×15 mm. | 14.96 ct. |
Pear Diamond Size Chart
Pear-cut (or teardrop-shaped) diamonds share similarities with oval-cut diamonds concerning
