Garnet size chart: carat to mm for every shape
By HeyGema™ · Updated
In short
A 1 carat round garnet measures about 6.2 mm across, against 6.5 mm for a 1 carat diamond. Garnet is denser than diamond (3.90 against 3.52), so it packs more weight into less space and faces up 3% narrower for the same weight.
- 6.2 mm1 carat round garnet
- 3.90density, g/cm3
- 6.5 to 7.5hardness, Mohs
Carat to mm calculator
About 6.2 x 6.2 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Garnet size chart: carat to mm
Face-up length and width in mm of a well-cut garnet at each weight and shape. Garnet is denser than diamond (3.90 against 3.52), so it packs more weight into less space and faces up 3% narrower for the same weight.
| Weight | Round | Oval | Cushion | Emerald cut | Pear | Princess |
|---|---|---|---|---|---|---|
| 0.25 ct | 3.9 | 4.9 x 3.3 | 3.4 x 3.4 | 4.3 x 3.0 | 5.2 x 3.3 | 3.3 x 3.3 |
| 0.5 ct | 4.9 | 6.1 x 4.2 | 4.3 x 4.3 | 5.4 x 3.8 | 6.5 x 4.2 | 4.2 x 4.2 |
| 0.75 ct | 5.7 | 7.0 x 4.8 | 4.9 x 4.9 | 6.1 x 4.4 | 7.5 x 4.8 | 4.8 x 4.8 |
| 1 ct | 6.2 | 7.7 x 5.3 | 5.4 x 5.4 | 6.8 x 4.8 | 8.2 x 5.3 | 5.3 x 5.3 |
| 1.5 ct | 7.1 | 8.9 x 6.1 | 6.2 x 6.2 | 7.7 x 5.5 | 9.4 x 6.1 | 6.1 x 6.1 |
| 2 ct | 7.9 | 9.7 x 6.7 | 6.8 x 6.8 | 8.5 x 6.1 | 10.3 x 6.7 | 6.7 x 6.7 |
| 3 ct | 9.0 | 11.2 x 7.7 | 7.8 x 7.8 | 9.8 x 7.0 | 11.8 x 7.7 | 7.7 x 7.7 |
| 4 ct | 9.9 | 12.3 x 8.4 | 8.6 x 8.6 | 10.7 x 7.7 | 13.0 x 8.4 | 8.4 x 8.4 |
| 5 ct | 10.7 | 13.2 x 9.1 | 9.3 x 9.3 | 11.6 x 8.3 | 14.0 x 9.1 | 9.1 x 9.1 |
| 10 ct | 13.4 | 16.7 x 11.5 | 11.7 x 11.7 | 14.6 x 10.4 | 17.7 x 11.5 | 11.5 x 11.5 |
Length x width in mm. A round stone shows one number, its diameter.
mm to carat for a round garnet
If you know the size, this is the weight. Measure across the widest point of the stone, face up.
- 4 mm
- Weight: 0.26 ct
- 5 mm
- Weight: 0.52 ct
- 6 mm
- Weight: 0.89 ct
- 7 mm
- Weight: 1.42 ct
- 8 mm
- Weight: 2.11 ct
- 9 mm
- Weight: 3.01 ct
- 10 mm
- Weight: 4.13 ct
- 12 mm
- Weight: 7.13 ct
Garnet against diamond
How wide a round garnet is next to a round diamond of the same weight.
- 0.5 ct
- Garnet: 4.9 mm
- Diamond: 5.1 mm
- Difference: -0.2 mm
- 1 ct
- Garnet: 6.2 mm
- Diamond: 6.5 mm
- Difference: -0.2 mm
- 2 ct
- Garnet: 7.9 mm
- Diamond: 8.1 mm
- Difference: -0.3 mm
- 3 ct
- Garnet: 9.0 mm
- Diamond: 9.3 mm
- Difference: -0.3 mm
- 5 ct
- Garnet: 10.7 mm
- Diamond: 11.0 mm
- Difference: -0.4 mm
Garnet properties
- Density used in the charts
- Value: 3.90 g/cm3 (range 3.6 to 4.3)
- Hardness (Mohs)
- Value: 6.5 to 7.5
- Refractive index
- Value: 1.714 to 1.888
A family of minerals. Density depends on the kind: pyrope 3.78, rhodolite about 3.84, almandine 4.05, spessartine 4.15. We use 3.9.