Round Brilliant Cut Diamond Size Chart

Round MM Size	Round Carat Weight
4 mm	0.25 ct
5.0 mm	0.50 ct
5.75 mm	0.75 ct
6.5 mm	1.00 ct
6.8 mm	1.25 ct
7.3 mm	1.50 ct
7.75 mm	1.75 ct
8 mm	2.00 ct
8.7 mm	2.50 ct
9.1 mm	3.00 ct
9.75 mm	3.50 ct
10.25 mm	4.00 ct
10.75 mm	4.50 ct
11 mm	5.00 ct

Round MM Size	Round Carat Weight
0.8 mm	0.0025 ct
1 mm	0.005 ct
1.1 mm	0.0067 ct
1.2 mm	0.009 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
2.2 mm	0.04 ct
2.5 mm	0.06 ct
2.75 mm	0.08 ct
3 mm	0.10 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

Round MM Size	Round 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	3.50 ct
10 mm	3.87 ct
10.25 mm	4.00 ct
10.5 mm	4.41 ct
10.75 mm	4.50 ct
11 mm	5.00 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

Diamond Shape Size Guides

Explore our comprehensive Diamond Size Charts by Shape to find the perfect fit for your jewelry designs

Round Diamond Size Chart

Princess Diamond Size Chart

Cushion Diamond Size Chart

Oval Diamond Size Chart

Emerald Diamond Size Chart

Pear Diamond Size Chart

Heart Diamond Size Chart

Marquise Diamond Size Chart

Asscher Diamond Size Chart

Radiant Diamond Size Chart

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Size Chart GUIDES

Round Shape Diamond Size Chart

Round Diamonds carat size chart in mm

The Round Cut Diamond is the most ideal and well-knowing shape from the beginning. If we go back to history, the first diamond engagement ring to exist was a round cut diamond. Round cut diamond engagement rings are best known for their charming design that can rock any look. The round diamond shape stands out as it allows the diamond to sparkle in its own beauty.

Hence, the most famous solitaire diamond engagement ring comes mostly in round cut shape. the publication of Marcel Tolkowsky’s thesis “Diamond Design,” the round shape diamond first comes into prominence. It is more seen and loved by the color white Because Its 57 to 58 facets bring out the most brilliance, fire, and sparkle of all the shapes.

Based on size

Generally, longer shaped fancy diamonds tend to appear bigger and broader to the naked eye when compared to a round or square-shaped diamonds of similar carat weight.

Based on length and width

The length into width measurements directly correspond to the shape of the diamond. It is a typical phenomenon for a well-cut diamond of a carat weight.

Based on the crown area

The crown area is the actual size of the diamond as how it would appear when viewed from the top. Visually a marquise shape would appear larger than a round shape in its top view.