Round Cut Diamond Carat Size
| Milimeters | Carat weight | Milimeters | Carat weight | |
| 1 mm | 0.005ct | 4.2mm | 0.3ct | |
| 1.8 mm | 0.025ct | 4.5 mm | 0.35 ct | |
| 2.4mm | 0.05ct | 4.8 mm | 0.4 ct | |
| 2.8 mm | 0.08ct | 5.2 mm | 0.5 ct | |
| 3mm | 0.1ct | 5.5 mm | 0.63 ct | |
| 3.2 mm | 0.12ct | 6 mm | 0.75 ct | |
| 3.5 mm | 0.16ct | 6.6 mm | 1 ct | |
| 3.8mm | 0.2ct | 7 mm | 1.25ct | |
| 4.0mm | 0.25ct | 8 .mm | 2.0ct |
