MM to Carat Weight Conversion Charts

Round

(also applies to European, Mine, Lonestar, Sunburst, and Portuguese)

Size (mm)	CZ ct wt	Diamond ct wt
1.25	0.013	0.010
1.50	0.023	0.015
1.75	0.037	0.020
2.00	0.06	0.03
2.25	0.08	0.04
2.50	0.10	0.05
2.75	0.15	0.08
3.00	0.18	0.11
3.50	0.29	0.17
4.00	0.43	0.25
4.50	0.61	0.36
5.00	0.79	0.46
5.50	1.13	0.66
6.00	1.43	0.84
6.50	1.75	1.03
7.00	2.17	1.28
7.50	2.84	1.67
8.00	3.46	2.04
8.50	4.13	2.43
9.00	4.68	2.75
9.50	5.69	3.35
10.00	6.58	3.87

Princess

(also applies to Quadrillion, Asscher, Flanders, and Cushion)

Size (mm)	CZ ct wt	Diamond ct wt
3.00	0.30	0.18
3.50	0.50	0.29
4.00	0.66	0.39
4.50	0.95	0.56
5.00	1.21	0.71
5.50	1.68	0.99
6.00	2.10	1.24
6.50	2.71	1.59
7.00	3.33	1.96
7.50	4.08	2.40
8.00	5.12	3.01
8.50	6.24	3.67
9.00	7.01	4.12
9.50	8.65	5.09
10.00	9.56	5.62

Heart

Size (mm)	CZ ct wt	Diamond ct wt
4.00	0.40	0.24
4.50	0.57	0.34
5.00	0.75	0.44
5.50	1.03	0.61
6.00	1.25	0.74
6.25	1.41	0.83
6.50	1.58	0.93
7.00	1.92	1.13
7.50	2.71	1.59
8.00	2.90	1.71
9.00	4.10	2.41
10.00	5.38	3.16