Cabochon-cut Diamond Size Chart
Carat to mm size chart for cabochon-cut Diamond, from 0.25ct to 40ct (at an L/W ratio of 1.5). The chart is interactive, meaning you can click on any stone to view it directly in the size simulator.
Gem sizes are shown in actual, real-world size, provided your device screen size is in diagonal. If this is not correct, change it here:
Gem sizes are shown in actual, real-world size, provided your device screen size is in diagonal. If this is not correct, change it here:
Actual size is set for screen
Gemstone:
Shape:
Diamond Size Chart (Cabochon Cut)
0.25ct
4.5×3 mm
4.5×3 mm
0.5ct
5.67×3.78 mm
5.67×3.78 mm
0.75ct
6.5×4.33 mm
6.5×4.33 mm
1ct
7.14×4.76 mm
7.14×4.76 mm
1.25ct
7.7×5.13 mm
7.7×5.13 mm
1.5ct
8.18×5.45 mm
8.18×5.45 mm
1.75ct
8.61×5.74 mm
8.61×5.74 mm
2ct
9×6 mm
9×6 mm
2.5ct
9.69×6.46 mm
9.69×6.46 mm
3ct
10.31×6.87 mm
10.31×6.87 mm
3.5ct
10.85×7.23 mm
10.85×7.23 mm
4ct
11.34×7.56 mm
11.34×7.56 mm
4.5ct
11.79×7.86 mm
11.79×7.86 mm
5ct
12.21×8.14 mm
12.21×8.14 mm
5.5ct
12.6×8.4 mm
12.6×8.4 mm
6ct
12.98×8.65 mm
12.98×8.65 mm
6.5ct
13.34×8.89 mm
13.34×8.89 mm
7ct
13.67×9.11 mm
13.67×9.11 mm
7.5ct
13.98×9.32 mm
13.98×9.32 mm
8ct
14.28×9.52 mm
14.28×9.52 mm
8.5ct
14.58×9.72 mm
14.58×9.72 mm
9ct
14.85×9.9 mm
14.85×9.9 mm
9.5ct
15.12×10.08 mm
15.12×10.08 mm
10ct
15.39×10.26 mm
15.39×10.26 mm
11ct
15.89×10.59 mm
15.89×10.59 mm
12ct
16.35×10.9 mm
16.35×10.9 mm
13ct
16.79×11.19 mm
16.79×11.19 mm
14ct
17.21×11.47 mm
17.21×11.47 mm
15ct
17.61×11.74 mm
17.61×11.74 mm
16ct
18×12 mm
18×12 mm
17ct
18.36×12.24 mm
18.36×12.24 mm
18ct
18.72×12.48 mm
18.72×12.48 mm
19ct
19.05×12.7 mm
19.05×12.7 mm
20ct
19.38×12.92 mm
19.38×12.92 mm
22ct
20.01×13.34 mm
20.01×13.34 mm
24ct
20.6×13.73 mm
20.6×13.73 mm
26ct
21.15×14.1 mm
21.15×14.1 mm
28ct
21.69×14.46 mm
21.69×14.46 mm
30ct
22.19×14.79 mm
22.19×14.79 mm
33ct
22.91×15.27 mm
22.91×15.27 mm
36ct
23.58×15.72 mm
23.58×15.72 mm
40ct
24.42×16.28 mm
24.42×16.28 mm
Length-to-width ratio: 1.5, Color:
Download Chart
Note: If you want to cut out the shapes and try them on your finger, print out the PDF chart. The image (png) chart will not print at actual size.
Carat-to-MM Conversion Table
Use this conversion table to quickly convert cabochon-cut Diamond carat weights to their approximate millimeter (mm) sizes:
| Carat Weight | MM Size |
|---|---|
| 0.25 ct | 4.5×3 mm |
| 0.5 ct | 5.67×3.78 mm |
| 0.75 ct | 6.5×4.33 mm |
| 1 ct | 7.14×4.76 mm |
| 1.25 ct | 7.7×5.13 mm |
| 1.5 ct | 8.18×5.45 mm |
| 1.75 ct | 8.61×5.74 mm |
| 2 ct | 9×6 mm |
| 2.5 ct | 9.69×6.46 mm |
| 3 ct | 10.31×6.87 mm |
| 3.5 ct | 10.85×7.23 mm |
| 4 ct | 11.34×7.56 mm |
| 4.5 ct | 11.79×7.86 mm |
| 5 ct | 12.21×8.14 mm |
| 5.5 ct | 12.6×8.4 mm |
| 6 ct | 12.98×8.65 mm |
| 6.5 ct | 13.34×8.89 mm |
| 7 ct | 13.67×9.11 mm |
| 7.5 ct | 13.98×9.32 mm |
| 8 ct | 14.28×9.52 mm |
| 8.5 ct | 14.58×9.72 mm |
| Carat Weight | MM Size |
|---|---|
| 9 ct | 14.85×9.9 mm |
| 9.5 ct | 15.12×10.08 mm |
| 10 ct | 15.39×10.26 mm |
| 11 ct | 15.89×10.59 mm |
| 12 ct | 16.35×10.9 mm |
| 13 ct | 16.79×11.19 mm |
| 14 ct | 17.21×11.47 mm |
| 15 ct | 17.61×11.74 mm |
| 16 ct | 18×12 mm |
| 17 ct | 18.36×12.24 mm |
| 18 ct | 18.72×12.48 mm |
| 19 ct | 19.05×12.7 mm |
| 20 ct | 19.38×12.92 mm |
| 22 ct | 20.01×13.34 mm |
| 24 ct | 20.6×13.73 mm |
| 26 ct | 21.15×14.1 mm |
| 28 ct | 21.69×14.46 mm |
| 30 ct | 22.19×14.79 mm |
| 33 ct | 22.91×15.27 mm |
| 36 ct | 23.58×15.72 mm |
| 40 ct | 24.42×16.28 mm |