Welcome to M.I.D. Diamonds Size Charts. Diamonds are cut to maximize beauty, so two stones with the exact same carat weight can look completely different in physical size depending on their shape. Developed by our expert gemologists to ensure maximum accuracy, this comprehensive tool helps you compare sizes across 10 of our classic shapes. Whether you are evaluating natural diamonds or exploring lab-grown options, use our detailed charts below to quickly translate millimeter (mm) measurements into estimated carat weights.
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. |
Understanding mm to carat and how diamond size in millimeters relates to carat weight is essential when choosing a diamond. Because shape and cut affect how a diamond appears, using an accurate mm to carat conversion chart helps you confidently compare sizes and weights for any diamond
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. |
MM Size | Carat Weight |
|---|---|
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. |
MM Size | Carat Weight |
|---|---|
3×2 mm. | 0.13 ct. |
4×2.5 mm. | 0.18 ct. |
4×3 mm. | 0.21 ct. |
5×3 mm. | 0.25 ct. |
5×4 mm. | 0.35 ct. |
6×4 mm. | 0.50 ct. |
6.5×4.5 mm. | 0.60 ct. |
7×5 mm. | 0.75 ct. |
7.5×5.5 mm. | 0.85 ct. |
7.7×5.7 mm. | 1.00 ct. |
8×6 mm. | 1.25 ct. |
8.5×6.5 mm. | 1.50 ct. |
10×6 mm. | 1.71 ct. |
8.7×6.7 mm. | 1.80 ct. |
9×7 mm. | 2.00 ct. |
10×8 mm. | 2.50 ct. |
11×7.50 mm. | 2.61 ct. |
13×8 mm. | 2.98 ct. |
11×8 mm. | 3.00 ct. |
MM Size | Carat Weight |
|---|---|
12×8 mm. | 3.00 ct. |
12×7 mm. | 3.12 ct. |
12×9 mm. | 3.44 ct. |
14×8 mm. | 3.47 ct. |
13×9 mm. | 4.11 ct. |
14×9 mm. | 4.25 ct. |
15×9 mm. | 5.06 ct. |
14×10 mm. | 5.41 ct. |
13×11 mm. | 5.65 ct. |
15×10 mm. | 5.75 ct. |
16×9 mm. | 5.86 ct. |
16×10 mm. | 6.27 ct. |
17×10 mm. | 6.46 ct. |
15×11 mm. | 7.36 ct. |
18×11 mm. | 8.14 ct. |
16×12 mm. | 8.99 ct. |
18×12 mm. | 9.35 ct. |
18×13 mm. | 10.21 ct. |
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. |
6.7×4.5 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. |
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. |
MM Size | Carat Weight |
|---|---|
1.5 mm. | 0.015 ct. |
1.75 mm. | 0.03 ct. |
2 mm. | 0.06 ct. |
2.25 mm. | 0.08 ct. |
2.5 mm. | 0.10 ct. |
2.75 mm. | 0.13 ct. |
3 mm. | 0.18 ct. |
3.25 mm. | 0.26 ct. |
3.5 mm. | 0.29 ct. |
3.75 mm. | 0.31 ct. |
4 mm. | 0.39 ct. |
4.25 mm. | 0.44 ct. |
4.5 mm. | 0.50 ct. |
4.75 mm. | 0.64 ct. |
5 mm. | 0.75 ct. |
5.25 mm. | 0.90 ct. |
5.5 mm. | 1.00 ct. |
5.75 mm. | 1.11 ct. |
6 mm. | 1.25 ct. |
6.25 mm. | 1.39 ct. |
MM Size | Carat Weight |
|---|---|
6.5 mm. | 1.50 ct. |
6.75 mm. | 1.75 ct. |
7 mm. | 2.00 ct. |
7.25 mm. | 2.01 ct. |
7.5 mm. | 2.50 ct. |
7.75 mm. | 2.74 ct. |
8 mm. | 3.00 ct. |
8.25 mm. | 3.24 ct. |
8.5 mm. | 3.67 ct. |
8.75 mm. | 4.10 ct. |
9 mm. | 4.12 ct. |
9.5 mm. | 5.09 ct. |
9.75 mm. | 5.36 ct. |
10 mm. | 5.62 ct. |
10.25 mm. | 5.76 ct. |
10.5 mm. | 5.99 ct. |
11 mm. | 7.44 ct. |
11.5 mm. | 9.44 ct. |
12 mm. | 9.52 ct. |
MM Size | Carat Weight |
|---|---|
4 mm. | 0.39 ct. |
4.5 mm. | 0.50 ct. |
5 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. |
MM Size | Carat Weight |
|---|---|
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. |
MM Size | Carat Weight |
|---|---|
5×3 mm. | 0.31 ct. |
4.5×3.5 mm. | 0.34 ct. |
6×3 mm. | 0.41 ct. |
6×4 mm. | 0.50 ct. |
6.5×4.5 mm. | 0.75 ct. |
7×5 mm. | 1.00 ct. |
7.3×5.5 mm. | 1.25 ct. |
7.5×5.8 mm. | 1.50 ct. |
8×6 mm. | 2.00 ct. |
8.5×6.5 mm. | 2.25 ct. |
9×7 mm. | 2.50 ct. |
9.5×7.5 mm. | 3.00 ct. |
10×7 mm. | 3.31 ct. |
MM Size | Carat Weight |
|---|---|
10×8 mm. | 3.50 ct. |
11×9 mm. | 5.05 ct. |
12×9 mm. | 6.06 ct. |
11.5×10 mm. | 6.45 ct. |
13×9 mm. | 6.54 ct. |
12×10 mm. | 6.79 ct. |
14×10 mm. | 8.47 ct. |
13×11 mm. | 9.33 ct. |
13.5×11.5 mm. | 10.19 ct. |
15×11 mm. | 11.48 ct. |
14×12 mm. | 12.14 ct. |
16×12 mm. | 14.22 ct. |
MM Size | Carat Weight |
|---|---|
3.5 mm. | 0.18 ct. |
4 mm. | 0.25 ct. |
4.25 mm. | 0.28 ct. |
4.5 mm. | 0.34 ct. |
4.75 mm. | 0.38 ct. |
5 mm. | 0.50 ct. |
5.5 mm. | 0.61 ct. |
6 mm. | 0.75 ct. |
6.25 mm. | 0.83 ct. |
6.5 mm. | 1.00 ct. |
7 mm. | 1.25 ct. |
7.5 mm. | 1.50 ct. |
MM Size | Carat Weight |
|---|---|
8 mm. | 2.00 ct. |
8.5 mm. | 2.50 ct. |
9 mm. | 3.00 ct. |
10 mm. | 3.50 ct. |
11 mm. | 4.41 ct. |
12 mm. | 5.66 ct. |
13 mm. | 7.88 ct. |
14 mm. | 9.38 ct. |
15 mm. | 10.79 ct. |
16 mm. | 13.27 ct. |
18 mm. | 15.33 ct.
|
MM Size | Carat Weight |
|---|---|
3×1.5 mm. | 0.025 ct. |
3.5×1.75 mm. | 0.065 ct. |
3.5×2 mm. | 0.07 ct. |
4×2 mm. | 0.10 ct. |
3.75×1.75 mm. | 0.11 ct. |
4.25×2.25 mm. | 0.12 ct. |
5×2.5 mm. | 0.14 ct. |
5.5×2.75 mm. | 0.16 ct. |
5.5×3 mm. | 0.18 ct. |
5×3 mm. | 0.20 ct. |
6.5×3 mm. | 0.23 ct. |
6×3 mm. | 0.25 ct. |
7×3 mm. | 0.30 ct. |
7.5×3.5 mm. | 0.33 ct. |
7×4 mm. | 0.34 ct. |
8×4 mm. | 0.50 ct. |
8.75×4.25 mm. | 0.70 ct. |
9×4.5 mm. | 0.75 ct. |
MM Size | Carat Weight |
|---|---|
9.5×4.7 mm. | 0.85 ct. |
10×5 mm. | 1.00 ct. |
11×5.5 mm. | 1.25 ct. |
11.5×6 mm. | 1.33 ct. |
12×6 mm. | 1.50 ct. |
13×6.5 mm. | 2.00 ct. |
14×7 mm. | 2.50 ct. |
15×7 mm. | 3.00 ct. |
14×8 mm. | 3.00 ct. |
15×7.5 mm. | 3.25 ct. |
15×8 mm. | 3.44 ct. |
16×8 mm. | 3.86 ct. |
16.5×8.25 mm. | 4.00 ct. |
17×8.5 mm. | 4.88 ct. |
17.5×10 mm. | 5.50 ct. |
20×8 mm. | 7.08 ct. |
20×10 mm. | 7.94 ct. |
20×11 mm. | 9.50 ct. |
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