Diamonds are measured in millimeters and carat weight. Regardless of the shape of the gemstone, both measurements can be found on the certificate, so pay attention to these numbers when shopping for diamonds.
When it comes to carats or weight, it doesn't make sense to measure diamonds that are already embedded in jewelry. Loose diamonds are most commonly measured.
Now you may be wonderingwhat are loose diamonds. The answer is quite simple: they are cut and polished diamonds that have not yet been made into a piece of jewelry.
If you have ever wonderedWhy are diamonds so expensive?and considered rare, the answer is because it takes around 250 tons of rock extraction to produce a single carat diamond. Knowing this, it is not difficult to understand why only 0.5ct makes a difference.a significant price difference.
Although carat weight is the standard measurement for diamonds, millimeter measurements are just as important. And today you will learn all about diamond sizes, proportions, charts and everything else.
So without further ado, let's dive into the gist of this diamond sizing chart!

Is the measurement of the diamond in millimeters important?
The millimeter gauge is just as important as the carat weight, as it indicates the actual size of the diamond. You may think that carats and millimeters change proportionally, but this is not always the case.
In other words, two diamonds can have the same carat weight and one can look larger than the other. This is because they have different facets.
Unusual diamond shapes such as ovals,Pera, and emerald look more striking compared to round diamonds.
So if you think size matters, don't go for the classic round shape.
In the case of non-round diamond shapes, the millimeter dimensions are a decisive factor, and not only because of the faceting. Great examples here are the pillow andSmaragdförmige diamond.
Cushion diamonds measure in millimeters if they are square, while emerald diamonds are rectangular in shape.
If this seems a bit confusing, a quick look at the diamond sizing charts will clear things up. So, keep reading!
Read relatives:What diamond carat is best for a ring?
Already have a setup?
Measuring diamonds in millimeters becomes even more important when purchasing a diamond for an existing earring or ring.
it can't be anyoneAsheromarquise diamond, For example. The gem size must be carefully chosen to match the style and setting.
Therefore, when purchasing, it is imperative that you choose a diamond with accurate measurements.
Read relatives:
- Types of settings for diamond earrings: options to consider
- Types of Diamond Settings: A Guide to Setting Styles

pointer and carat
One term you will definitely hear when shopping for diamonds is "pointers" or "points". So what does that mean?
In short, points are fractions of a carat.
when a diamond weighs0.5 carats, is a 50 point diamond. By this logic, a 100 point diamond refers to a1 caratStone, 150 points means that it is a1.5 caratsstone and so on.
You will most likely hear this term of retail and wholesale when shopping for jewelry, especially engagement rings. That's because these are smaller.accent diamondsand easier to describe when speakingPoints.
Although each diamond is unique, it's a good idea to know the average millimeter measurements for different carat weights when purchasing one.
By knowing standard sizes and measurements, you'll be more likely to make the best possible decision within a given budget.
Read relatives:
- Is a 0.5 carat (half carat) diamond too small?
- Is a 2 carat diamond big?

The Ultimate Guide to Diamond Cut Charts
Now that you're familiar with the connections between carat weight and millimeter measurement, let's move on to the real numbers.
List?

Round Diamond Size Chart
Did you know that round diamonds are themost popular shapeUp to 64% of young adults choose a round diamond as the centerpiece of their engagement ring!
Learn more:Round Brilliant Cut Diamonds: Everything You Need to Know
Size (in millimeters) | carat weight |
---|---|
0,80mm | 0,0025 kt. |
1,00mm | 0,0050 kt. |
1,12mm | 0,0067 kt. |
1,15mm | 0,0075 kt. |
1,25mm | 0,010ct. |
1,50mm | 0,015ct. |
1,75mm | 0.020 knots |
1,80mm | 0,025 kt. |
2,00mm | 0.030 knots |
2,25mm | 0,040 kt. |
2,50mm | 0.060 knots |
2,75 mm | 0.080 knots |
3,00mm | 0,11ct. |
3,25mm | 0.14 knots |
3,50mm | 0.17 knots |
3,75 mm | 0,21ct. |
4,00mm | 0,25ct. |
4,25mm | 0.28 knots |
4,50mm | 0.36 knots |
4,75mm | 0,44ct. |
5,00mm | 0,5ct. |
5,25mm | 0,56 kt. |
5,50mm | 0,66 kt. |
5,75 mm | 0,75ct. |
6,00mm | 0,84 kt. |
6,25mm | 0,93ct. |
6,50mm | 1,00ct. |
6,80mm | 1,25ct. |
7,00mm | 1,30ct. |
7,30mm | 1,50ct. |
7,50mm | 1,67 ct. |
7,75mm | 1,75ct. |
8,00mm | 2,00ct. |
8,25mm | 2,11 ct. |
8,50mm | 2,43 kt. |
8,70mm | 2,50ct. |
9,00mm | 2,75ct. |
9,10mm | 3,00ct. |
9,50mm | 3,35ct. |
9,75mm | 3,61ct. |
10,00mm | 3,87ct. |
10,25mm | 4,16 kt. |
10,50mm | 4,41 ct. |
10,75 mm | 4,57 ct. |
11,00mm | 4,91ct. |
11,25mm | 5,49 ct. |
11,50mm | 5,85ct. |
12,00mm | 6,84 kt. |
12,25mm | 7,26 kt. |
12,50mm | 7,36 kt. |
12,75 mm | 7,52ct. |
13,00mm | 8,51ct. |
13,50mm | 9,53ct. |
14,00mm | 10,49 ct. |
15,00mm | 12.89 carats |
16,00mm | 16,06 ct. |
17,00mm | 18.00 knots |

Princess Diamond Cut Chart
This contemporary diamond cut features a sharp, geometric pyramid shape, characterized by strong lines and four beveled sides. This cut has been around since the 1980s and is known for the incredible amount of fire it offers.
Learn more:Princess cut diamonds: everything you need to know
Size (in millimeters) | carat weight |
---|---|
1,50mm | 0,015ct. |
1,75mm | 0,03ct. |
2,00mm | 0,06ct. |
2,25mm | 0.08 knots |
2,50mm | 0,10ct. |
2,75 mm | 0.13 knots |
3,00mm | 0.18 knots |
3,25mm | 0.26 knots |
3,50mm | 0.29 knots |
3,75 mm | 0,31ct. |
4,00mm | 0.39 knots |
4,25mm | 0,44ct. |
4,50mm | 0,50ct. |
4,75mm | 0.64 carats |
5,00mm | 0,75ct. |
5,25mm | 0,75ct. |
5,50mm | 1,00ct. |
5,75 mm | 1,11 ct. |
6,00mm | 1,25ct. |
6,25mm | 1,39ct. |
6,50mm | 1,50ct. |
6,75mm | 1,75ct. |
7,00mm | 2,00ct. |

Pillow Diamond Size Chart
cushion cut diamondsthey are square in shape and have larger brilliant-cut facets, but with rounded corners. They resemble a pillow, hence the name.
Size (in millimeters) | carat weight |
---|---|
4,2mm | 0,40 ct. |
4,9 mm | 0,50ct. |
5,25mm | 0,75ct. |
5,5mm | 1,00ct. |
6 mm | 1,25ct. |
6,5mm | 1,50ct. |
7 mm | 2,00ct. |
7,5mm | 2,50ct. |
8 mm | 3,00ct. |
8,5mm | 3,50ct. |
9 mm | 4.12 carats |
9,5mm | 5,09 ct. |
10 mm | 5,62ct. |
11 mm | 7,44 kt. |
12 mm | 9,52ct. |
13 mm | 12,66 kt. |

Emerald Diamond Cut Chart
emerald cut diamondsthey are among the oldest cuts, dating back to the 16th century. They are known for their elongated rectangular shape, stepped cuts, and linear facets.
Size (in millimeters) | carat weight |
---|---|
3 × 2 mm | 0,10ct. |
3,5 × 2mm | 0.12 knots |
4 × 2 mm | 0,15ct. |
4x3mm | 0,20ct. |
5x3mm | 0.29 knots |
5,5 × 3,5 mm | 0,46 kt. |
6x4mm | 0,50ct. |
6,5 × 4,5 mm | 0,75ct. |
6,5 × 4,5 mm | 0,88 kt. |
7x5mm | 1,00ct. |
7,3 × 5,3 mm | 1,25ct. |
7,5 × 5,5 mm | 1,50ct. |
8x6mm | 1,75ct. |
8,5 × 6,5 mm | 2,00ct. |
9x7mm | 2,50ct. |
10 × 7,5 mm | 3,00ct. |
9,5 × 7,5 mm | 3,21ct. |
10 × 8 mm | 3,79ct. |
11×9mm | 5,21 ct. |
12 × 8 mm | 5,34 kt. |
12 × 10 mm | 6,00ct. |
14 × 8mm | 6,25ct. |
13×9mm | 6,38ct. |
14 × 10 mm | 8,48 kt. |
13 × 11 mm | 9.13 carats |
14 × 12 mm | 11,26 kt. |
16 × 12 mm | 14.22 carats |
17 × 13 mm | 16,50ct. |
Read relatives:Emerald Court vs. Radiant Cut

Oval Diamond Size Chart
If you likebrillianceof a round diamond but in more exclusive looking packagingoval cut diamondyou should consider!
Size (in millimeters) | carat weight |
---|---|
4,5 × 3,5 mm | 0,21ct. |
5x3mm | 0,21ct. |
5,5 × 3,5 mm | 0.33 knots |
5x4mm | 0.35 knots |
6x4mm | 0,50ct. |
6x5mm | 0,61ct. |
6,5 × 4,5 mm | 0.65 knots |
7x5mm | 0,75ct. |
7,7 × 5,7 mm | 1,00ct. |
8x6mm | 1,25ct. |
9x6mm | 1,41 ct. |
8,5 × 6,5 mm | 1,50ct. |
9x7mm | 2,00ct. |
10 × 8 mm | 2,50ct. |
10,5 × 8,5 mm | 2,88 kt. |
12 × 8 mm | 3,00ct. |
11×9mm | 3,85ct. |
12 × 10 mm | 5,05ct. |
14 × 10 mm | 5.81 ct. |
13 × 11 mm | 6,05ct. |
14 × 12 mm | 8,21 ct. |
15 × 12 mm | 8,76 kt. |
16 × 12 mm | 9.32 knots |
16 × 14 mm | 11,88 kt. |
18 × 13 mm | 12,86 kt. |
20 × 15 mm | 14,96 kt. |

Pear Diamond Cut Chart
A mixture of round and marquise, but with a tapered point on one side, adiamante pearit has the exceptional ability to hide any imperfections within the gemstone. It also appears larger than a round cut diamond.
Size (in millimeters) | carat weight | Size (in millimeters) | carat weight |
---|---|---|---|
3 × 2 mm | 0.13 knots | 12 × 8 mm | 3,00ct. |
4 × 2,5 mm | 0.18 knots | 12 × 7 mm | 3,12 ct. |
4x3mm | 0,21ct. | 12×9mm | 3,44ct. |
5x3mm | 0,25ct. | 14 × 8mm | 3,47ct. |
5x4mm | 0.35 knots | 13×9mm | 4,11 ct. |
6x4mm | 0,50ct. | 14×9mm | 4,25ct. |
6,5 × 4,5 mm | 0,60ct. | 15×9mm | 5,06 kt. |
7x5mm | 0,75ct. | 14 × 10 mm | 5,41 ct. |
7,5 × 5,5 mm | 0,85ct. | 13 × 11 mm | 5,65ct. |
7,7 × 5,7 mm | 1,00ct. | 15 × 10 mm | 5,75ct. |
8x6mm | 1,25ct. | 16×9mm | 5,86 kt. |
8,5 × 6,5 mm | 1,50ct. | 16 × 10 mm | 6.27 knots |
10 × 6mm | 1,71ct. | 17 × 10 mm | 6,46 kt. |
8,7 × 6,7 mm | 1,80 ct. | 15 × 11 mm | 7,36 kt. |
9x7mm | 2,00ct. | 18 × 11 mm | 8,14 kt. |
10 × 8 mm | 2,50ct. | 16 × 12 mm | 8,99ct. |
11 × 7,50 mm | 2,61ct. | 18 × 12 mm | 9,35ct. |
13 × 8 mm | 2,98 kt. | 18 × 13 mm | 10,21ct. |
11 × 8 mm | 3,00ct. | 19 × 14 mm | 11,70ct. |

Marquise Diamond Cut Chart
This diamond cut is characterized by its elongated shape with pointed ends and 58 facets that create the illusion of larger size.
Size (in millimeters) | carat weight | Size (in millimeters) | carat weight |
---|---|---|---|
3 × 1,5 mm | 0,025 kt. | 9,5 × 2mm | 0,85ct. |
3,5 × 1,75 mm | 0,065 kt. | 10 × 5 mm | 1,00ct. |
3,5 × 2mm | 0.07 knots | 11 × 5,5 mm | 1,25ct. |
4 × 2 mm | 0,10ct. | 11,5 × 6mm | 1,33ct. |
3,75 × 1,75 mm | 0,11ct. | 12 × 6mm | 1,50ct. |
4,25 × 2,25 mm | 0.12 knots | 13 × 6,5mm | 2,00ct. |
5 × 2,5 mm | 0.14 knots | 14 × 7 mm | 2,50ct. |
5,5 × 2,75 mm | 0.16 knots | 15 × 7 mm | 3,00ct. |
5.5 × 3mm | 0.18 knots | 14 × 8mm | 3,00ct. |
5x3mm | 0,20ct. | 15 × 7,5 mm | 3,25ct. |
6.5 × 3mm | 0.23 knots | 15 × 8 mm | 3,44ct. |
6x3mm | 0,25ct. | 16 × 8 mm | 3,86 kt. |
7x3mm | 0,30ct. | 16,5 × 8,25 mm | 4,00ct. |
7,5 × 3,5 mm | 0.33 knots | 17 × 8,5 mm | 4.88 ct. |
7x4mm | 0.34 knots | 17,5 × 10 mm | 5,50ct. |
8x4mm | 0,50ct. | 20 × 8 mm | 7,08 kt. |
8,75 × 4,25 mm | 0,70ct. | 20 × 10 mm | 7,94 kt. |
9 × 4,5mm | 0,75ct. | 20 × 11 mm | 9,50ct. |

Asscher Diamond Cut Chart
The Asscher Cut– invented in 1902 – is an excellent alternative to the emerald cut. Its 58 facets also promise more shine!
Size (in millimeters) | carat weight |
---|---|
4 mm | 0.39 knots |
4,5mm | 0,50ct. |
5 mm | 0,75ct. |
5,5mm | 1,00ct. |
6 mm | 1,25ct. |
6,5mm | 1,50ct. |
7 mm | 2,00ct. |
7,5mm | 2,50ct. |
8 mm | 3,00ct. |
8,5mm | 3,50ct. |
9 mm | 4.12 carats |
9,5mm | 5,09 ct. |
10 mm | 5,62ct. |
11 mm | 7,44 kt. |
12 mm | 9,52ct. |
13 mm | 12,66 kt. |

Radiant Diamond Cut Chart
This modern shape was invented in 1977 and is characterized by its vibrant and impressive shine. Combine the advantages of a brilliant cut (like a round cut) and a step cut (like an emerald) in one!
Learn more:Radiant Cut Diamonds: Everything You Need to Know
Size (in millimeters) | carat weight |
---|---|
5x3mm | 0,31ct. |
4,5 × 3,5 mm | 0.34 knots |
6x3mm | 0.41 ct. |
6x4mm | 0,50ct. |
6,5 × 4,5 mm | 0,75ct. |
7x5mm | 1,00ct. |
7,3 × 5,5 mm | 1,25ct. |
7,5 × 5,8 mm | 1,50ct. |
8x6mm | 2,00ct. |
8,5 × 6,5 mm | 2,25ct. |
9x7mm | 2,50ct. |
9,5 × 7,5 mm | 3,00ct. |
10 × 7 mm | 3,31ct. |
10 × 8 mm | 3,50ct. |
11×9mm | 5,05ct. |
12×9mm | 6,06 kt. |
11,5 × 10 mm | 6,45ct. |
13×9mm | 6.54 carats |
12 × 10 mm | 6,79ct. |
14 × 10 mm | 8,47 kt. |
13 × 11 mm | 9,33 kt. |
13,5 × 11,5 mm | 10,19 ct. |
15 × 11 mm | 11.48 carats |
14 × 12 mm | 12.14 carats |
16 × 12 mm | 14.22 carats |
17 × 13 mm | 16,22 kt. |
Read relatives:
- What size diamond is considered large?
- How can you determine the size of a diamond?