Round Cut Diamond Size Chart (MM)

Discover how different carat weights translate into actual millimeter sizes for round diamonds, helping you choose the perfect fit for your style and setting.

Round Cut Diamond Sizes

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.	3.61 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.

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