Ideal Cut Round Diamond Melee Size Chart
A calibration reference for jewelers: millimeter sizes, average carat weights, and sieve plate numbers for natural ideal cut round melee diamonds.
Millimeter Size to Average Carat Weight
Average carat weight per stone for ideal cut round brilliant melee diamonds, 0.7 mm to 3.8 mm. Diamonds per carat is rounded and approximate.
| Diameter (mm) | AVG. WEIGHT (CARAT) | APPROX. DIAMONDS PER CARAT |
|---|---|---|
| 0.7 mm | 0.0022 | 455 |
| 0.8 mm | 0.003 | 333 |
| 0.9 mm | 0.004 | 250 |
| 1.0 mm | 0.005 | 200 |
| 1.1 mm | 0.006 | 167 |
| 1.2 mm | 0.0075 | 133 |
| 1.3 mm | 0.0095 | 105 |
| 1.4 mm | 0.012 | 83 |
| 1.5 mm | 0.015 | 67 |
| 1.6 mm | 0.017 | 59 |
| 1.7 mm | 0.02 | 50 |
| 1.8 mm | 0.025 | 40 |
| 1.9 mm | 0.03 | 33 |
| 2.0 mm | 0.035 | 29 |
| 2.1 mm | 0.04 | 25 |
| 2.2 mm | 0.045 | 22 |
| 2.3 mm | 0.05 | 20 |
| 2.4 mm | 0.055 | 18 |
| 2.5 mm | 0.06 | 17 |
| 2.6 mm | 0.07 | 14 |
| 2.7 mm | 0.08 | 13 |
| 2.8 mm | 0.09 | 11 |
| 2.9 mm | 0.095 | 11 |
| 3.0 mm | 0.107 | 9 |
| 3.1 mm | 0.12 | 8 |
| 3.2 mm | 0.13 | 8 |
| 3.3 mm | 0.145 | 7 |
| 3.4 mm | 0.155 | 6 |
| 3.5 mm | 0.17 | 6 |
| 3.6 mm | 0.18 | 6 |
| 3.7 mm | 0.2 | 5 |
| 3.8 mm | 0.22 | 5 |
Diamond Sieve Plate Number to Hole Diameter
Standard 65-plate diamond sieve set, No. 000000 to 14.0. Each plate number maps to its hole diameter in millimeters.
| Plate No. | Hole diameter (mm) |
|---|---|
| 000000 | 0.60 mm |
| 000000.5 | 0.65 mm |
| 00000 | 0.70 mm |
| 00000.5 | 0.75 mm |
| 0000 | 0.80 mm |
| 0000.5 | 0.85 mm |
| 000 | 0.90 mm |
| 000.5 | 0.95 mm |
| 00 | 1.00 mm |
| 00.5 | 1.05 mm |
| 0 | 1.10 mm |
| 0.5 | 1.125 mm |
| 1 | 1.15 mm |
| 1.25 | 1.175 mm |
| 1.5 | 1.20 mm |
| 1.75 | 1.225 mm |
| 2 | 1.25 mm |
| 2.25 | 1.275 mm |
| 2.5 | 1.30 mm |
| 2.75 | 1.325 mm |
| 3 | 1.35 mm |
| 3.25 | 1.375 mm |
| 3.5 | 1.40 mm |
| 3.75 | 1.425 mm |
| 4 | 1.45 mm |
| 4.25 | 1.475 mm |
| 4.5 | 1.50 mm |
| 4.75 | 1.525 mm |
| 5 | 1.55 mm |
| 5.25 | 1.575 mm |
| 5.5 | 1.60 mm |
| 5.75 | 1.65 mm |
| 6 | 1.70 mm |
| 6.25 | 1.75 mm |
| 6.5 | 1.80 mm |
| 6.75 | 1.85 mm |
| 7.0 | 1.90 mm |
| 7.25 | 1.95 mm |
| 7.5 | 2.00 mm |
| 7.75 | 2.05 mm |
| 8.0 | 2.10 mm |
| 8.25 | 2.15 mm |
| 8.5 | 2.20 mm |
| 8.75 | 2.25 mm |
| 9.0 | 2.30 mm |
| 9.25 | 2.35 mm |
| 9.5 | 2.40 mm |
| 9.75 | 2.45 mm |
| 10.0 | 2.50 mm |
| 10.25 | 2.55 mm |
| 10.5 | 2.60 mm |
| 10.75 | 2.65 mm |
| 11.0 | 2.70 mm |
| 11.25 | 2.75 mm |
| 11.5 | 2.80 mm |
| 11.75 | 2.85 mm |
| 12 | 2.90 mm |
| 12.25 | 2.95 mm |
| 12.5 | 3.00 mm |
| 12.75 | 3.05 mm |
| 13.0 | 3.10 mm |
| 13.25 | 3.15 mm |
| 13.5 | 3.20 mm |
| 13.75 | 3.25 mm |
| 14.0 | 3.30 mm |
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