Round Diamonds
This round diamond size chart or diamond weight chart lists ideal or near ideal sizes and carat weights. This means that if a diamond has an ideal cut it will have very specific dimensions which lend themselves towards this type of measurement. This is a jewelry industry standard, specifically for natural diamonds. If a diamond has a cut which is further from ideal then the dimensions will be off, however, using this tool will still provide a rough estimation of size to carat weight.
| Millimeter Size | Carat Weight | Stones Per Carat | Carat Weight Fraction | Sieve Plate |
|---|---|---|---|---|
| 0.70 - 0.75 mm | 0.0017 ct | 630 | ||
| 0.75 - 0.80 mm | 0.0019 ct | 570 | ||
| 0.80 - 0.85 mm | 0.0024 ct | 380 | ||
| 0.85 - 0.90 mm | 0.0029 ct | 320 | ||
| 0.90 - 0.95 mm | 0.0034 ct | 295 | ||
| 0.95 - 1.00 mm | 0.0040 ct | 250 | 0.00 | |
| 1.00 - 1.05 mm | 0.0045 ct | 220 | 9/2000 ct | |
| 1.12 mm | 0.0067 ct | 67/10000 | ||
| 1.15 mm | 0.0075 ct | 3/400 | ||
| 1.3 mm | 0.01 ct | 1/100 | ||
| 1.5 mm | 0.015 ct | 3/200 ct | ||
| 1.7 mm | 0.02 ct | 1/50 ct | ||
| 1.8 mm | 0.025 ct | 1/40 ct | ||
| 2.0 mm | 0.03 ct | 3/100 ct | ||
| 2.5 mm | 0.05 ct | 5/100 ct | ||
| 2.7 mm | 0.07 ct | 7/100 ct | ||
| 3.0 mm | 0.10 ct | 1/10 ct | ||
| 3.4 mm | 0.15 ct | 3/20 ct | ||
| 3.8 mm | 0.20 ct | 1/5 ct | ||
| 4.1 mm | 0.25 ct | 1/4 ct | ||
| 4.4 mm | 0.33 ct | 33/100 ct | ||
| 4.8 mm | 0.40 ct | 4/10 ct | ||
| 5.2 mm | 0.50 ct | 1/2 ct | ||
| 5.6 mm | 0.65 ct | 13/20 ct | ||
| 5.9 mm | 0.75 ct | 3/4 ct | ||
| 6.2 mm | 0.85 ct | 17/20 ct | ||
| 6.5 mm | 1.00 ct | 1/1 ct | ||
| 7.0 mm | 1.25 ct | 5/4 ct1 | ||
| 7.4 mm | 1.50 ct | 3/2 ct1 | ||
| 7.8 mm | 1.75 ct | 7/4 ct1 | ||
| 8.2 mm | 2.00 ct | 2/1 ct1 | ||
| 8.6 mm | 2.25 ct | 9/4 ct1 | ||
| 9.0 mm | 2.50 ct | 5/2 ct1 | ||
| 9.3 mm | 3.00 ct | 3/1 ct1 | ||
| 10.2 mm | 4.00 ct | 4/1 ct1 | ||
| 11.00 mm | 5.00 ct | 5/1 ct1 | ||
| 11.7 mm | 6.00 ct | 6/1 ct1 | ||
| 12.4 mm | 7.00 ct | 7/1 ct1 | ||
| 13.0 mm | 8.00 ct | 8/1 ct1 |
1 Carat Weight Fractions for diamonds larger than one carat are represented as an improper fraction.
