While diamonds that are the same shape and carat weight can have different millimeter measurements due to the differences in cut parameters, there is even a bigger differences in millimeter size between diamonds that are different shapes but the same carat weight.
Often diamond shoppers are seeking the biggest millimeter size and are not sure what shape will give them that. Other shoppers wonder what the size difference is between carat weights. The following chart provides some approximate millimeter lengths and widths for various shapes and carat weights.
Round mm Marquise mm Princess mm Pear mm Oval mm Emerald mm Heart mm Triangle mm Please note that these are approximate measurements and actual millimeter sizes can vary based on the depth percentages, table percentages, girdle thickness and other cut parameters.
Carat
0.05
2.4
3.5×2
1.8×1.8
3×2
-
-
-
2.5×2.5×2.5
0.10
3.0
4.5×2.5
2.5×2.5
4×2.5
-
3×2
3×3
3x3x3
0.15
3.4
5×2.5
2.8×2.8
4.5×3
-
3.5×2.5
3.5×3.5
3.5×3.5×3.5
0.18
3.7
-
-
-
-
-
-
4x4x4
0.20
3.8
6×3
3×3
5×3.5
4.5×2.5
-
3.5×3.5
-
0.22
3.9
-
-
-
-
-
-
-
0.23
4.0
-
-
-
-
-
-
-
0.25
4.1
6.5×3.5
3.3×3.3
5.5×3.5
5×3
4.5×3.5
4×4
4.5×4.5×4.5
0.30
4.2
-
3.7×3.7
-
-
-
-
-
0.33
4.4
-
-
-
-
-
-
-
0.35
4.5
7.5×3.5
3.8×3.8
6.5×3.5
-
5×3
4.5×4.5
5x5x5
0.38
4.6
-
-
-
5×4
-
-
-
0.40
4.8
8×4
4×4
6.5×4.5
5.5×4
-
-
5.5×5.5×5.5
0.47
5.0
-
-
-
-
-
-
-
0.50
5.2
8.5×4
4.5×4.5
7×4.5
6.4
5.5×4.5
5.5
6x6x6
0.60
5.4
-
4.7×4.7
-
-
-
-
-
0.65
5.6
9×4.5
-
7.5×4.5
6.5×4.5
-
5.5×5.5
6.5×6.5×6.5
0.75
5.8
9.5×4.5
5×5
8×5
7×5
6×4
6×6
7x7x7
0.80
6.0
-
-
-
-
-
-
-
0.85
6.2
10×5
-
8.5×5
-
6.5×5
-
7.5×7.5×7.5
0.95
6.4
-
-
-
-
-
-
-
1.00
6.5
10.5×5
6×6
9×5.5
7.5×5.5
7×5
6.5×6.5
8x8x8
1.10
6.6
-
-
-
-
-
-
-
1.17
6.8
-
-
-
-
-
-
-
1.25
7.0
11×5.5
-
9.5×6
8×6
-
-
8.5×8.5×8.5
1.33
7.2
-
-
-
-
-
-
-
1.50
7.4
12×6
6.5×6.5
10×6
8.5×6.5
8×6
7×7
9x9x9
1.60
7.6
-
-
-
-
-
-
-
1.75
7.8
-
-
10.5×6.5
9×6
-
7.5×7.5
9.5×9.5×9.5
1.90
8.0
-
-
-
-
-
-
-
2.00
8.2
13×6.5
7×7
11×7
9×7
8.5×6
8×8
10x10x10
2.15
8.4
-
-
-
-
-
-
-
2.25
8.6
13.5×7
-
11.5×7
-
-
-
-
2.50
8.8
14×7
7.5×7.5
12×7.5
9×7.5
9×7
8.5×8.5
-
2.65
9.0
-
-
-
-
-
-
-
2.75
9.1
14.5×7.5
-
12.5×7.5
9.5×7.5
-
-
-
2.85
9.2
-
-
-
-
-
-
-
3.00
9.4
15×7.5
8×8
12.5×8
10×8
10×8
9×9
-
3.15
9.6
-
-
-
-
-
-
-
3.25
9.7
-
-
13×8
-
-
-
-
3.35
9.8
-
-
-
-
-
-
-
3.50
10.0
16×8
-
13.5×8.5
10×8.5
-
9.5×9.5
-
3.60
10.1
-
-
-
-
-
-
-
3.75
10.2
-
-
14×8.5
-
-
-
-
4.00
10.4
16.5×8.5
-
14×9
11×9
11×9
10×10
-
4.25
10.6
-
-
-
-
-
-
-
4.75
11.0
-
-
-
-
-
-
-
5.00
11.2
18×9
-
15×9.5
12×10
12×10
11×11
-