Cubic Zirconia Size Chart (Round)
Carat to mm size chart for round-cut Cubic Zirconia, from 0.25ct to 40ct. 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:
Cubic Zirconia Size Chart (Round Cut)
0.25ct
3.4×3.4 mm
3.4×3.4 mm
0.5ct
4.28×4.28 mm
4.28×4.28 mm
0.75ct
4.9×4.9 mm
4.9×4.9 mm
1ct
5.4×5.4 mm
5.4×5.4 mm
1.25ct
5.81×5.81 mm
5.81×5.81 mm
1.5ct
6.18×6.18 mm
6.18×6.18 mm
1.75ct
6.5×6.5 mm
6.5×6.5 mm
2ct
6.8×6.8 mm
6.8×6.8 mm
2.5ct
7.32×7.32 mm
7.32×7.32 mm
3ct
7.78×7.78 mm
7.78×7.78 mm
3.5ct
8.19×8.19 mm
8.19×8.19 mm
4ct
8.56×8.56 mm
8.56×8.56 mm
4.5ct
8.91×8.91 mm
8.91×8.91 mm
5ct
9.23×9.23 mm
9.23×9.23 mm
5.5ct
9.52×9.52 mm
9.52×9.52 mm
6ct
9.8×9.8 mm
9.8×9.8 mm
6.5ct
10.07×10.07 mm
10.07×10.07 mm
7ct
10.32×10.32 mm
10.32×10.32 mm
7.5ct
10.56×10.56 mm
10.56×10.56 mm
8ct
10.79×10.79 mm
10.79×10.79 mm
8.5ct
11.01×11.01 mm
11.01×11.01 mm
9ct
11.22×11.22 mm
11.22×11.22 mm
9.5ct
11.43×11.43 mm
11.43×11.43 mm
10ct
11.62×11.62 mm
11.62×11.62 mm
11ct
12×12 mm
12×12 mm
12ct
12.35×12.35 mm
12.35×12.35 mm
13ct
12.69×12.69 mm
12.69×12.69 mm
14ct
13×13 mm
13×13 mm
15ct
13.31×13.31 mm
13.31×13.31 mm
16ct
13.59×13.59 mm
13.59×13.59 mm
17ct
13.87×13.87 mm
13.87×13.87 mm
18ct
14.14×14.14 mm
14.14×14.14 mm
19ct
14.4×14.4 mm
14.4×14.4 mm
20ct
14.64×14.64 mm
14.64×14.64 mm
22ct
15.12×15.12 mm
15.12×15.12 mm
24ct
15.56×15.56 mm
15.56×15.56 mm
26ct
15.98×15.98 mm
15.98×15.98 mm
28ct
16.38×16.38 mm
16.38×16.38 mm
30ct
16.76×16.76 mm
16.76×16.76 mm
33ct
17.3×17.3 mm
17.3×17.3 mm
36ct
17.81×17.81 mm
17.81×17.81 mm
40ct
18.45×18.45 mm
18.45×18.45 mm
Length-to-width ratio: 1, 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 round-cut Cubic Zirconia carat weights to their approximate millimeter (mm) sizes:
| Carat Weight | MM Size |
|---|---|
| 0.25 ct | 3.4×3.4 mm |
| 0.5 ct | 4.28×4.28 mm |
| 0.75 ct | 4.9×4.9 mm |
| 1 ct | 5.4×5.4 mm |
| 1.25 ct | 5.81×5.81 mm |
| 1.5 ct | 6.18×6.18 mm |
| 1.75 ct | 6.5×6.5 mm |
| 2 ct | 6.8×6.8 mm |
| 2.5 ct | 7.32×7.32 mm |
| 3 ct | 7.78×7.78 mm |
| 3.5 ct | 8.19×8.19 mm |
| 4 ct | 8.56×8.56 mm |
| 4.5 ct | 8.91×8.91 mm |
| 5 ct | 9.23×9.23 mm |
| 5.5 ct | 9.52×9.52 mm |
| 6 ct | 9.8×9.8 mm |
| 6.5 ct | 10.07×10.07 mm |
| 7 ct | 10.32×10.32 mm |
| 7.5 ct | 10.56×10.56 mm |
| 8 ct | 10.79×10.79 mm |
| 8.5 ct | 11.01×11.01 mm |
| Carat Weight | MM Size |
|---|---|
| 9 ct | 11.22×11.22 mm |
| 9.5 ct | 11.43×11.43 mm |
| 10 ct | 11.62×11.62 mm |
| 11 ct | 12×12 mm |
| 12 ct | 12.35×12.35 mm |
| 13 ct | 12.69×12.69 mm |
| 14 ct | 13×13 mm |
| 15 ct | 13.31×13.31 mm |
| 16 ct | 13.59×13.59 mm |
| 17 ct | 13.87×13.87 mm |
| 18 ct | 14.14×14.14 mm |
| 19 ct | 14.4×14.4 mm |
| 20 ct | 14.64×14.64 mm |
| 22 ct | 15.12×15.12 mm |
| 24 ct | 15.56×15.56 mm |
| 26 ct | 15.98×15.98 mm |
| 28 ct | 16.38×16.38 mm |
| 30 ct | 16.76×16.76 mm |
| 33 ct | 17.3×17.3 mm |
| 36 ct | 17.81×17.81 mm |
| 40 ct | 18.45×18.45 mm |