Technical reference
Melee size guide
Melee is bought by millimetre, not by carat. This reference translates common calibrated mm bands into approximate weights and stone counts so you can plan a production run or a repair before you order.
Round brilliant: mm to carat
| Diameter (mm) | Approx. weight (ct) | Stones per carat |
|---|---|---|
| 0.90 – 1.00 | 0.005 | ~200 |
| 1.00 – 1.10 | 0.006 | ~170 |
| 1.10 – 1.20 | 0.008 | ~125 |
| 1.20 – 1.30 | 0.009 | ~110 |
| 1.30 – 1.40 | 0.011 | ~90 |
| 1.40 – 1.50 | 0.015 | ~67 |
| 1.50 – 1.60 | 0.017 | ~59 |
| 1.60 – 1.70 | 0.020 | ~50 |
| 1.70 – 1.80 | 0.025 | ~40 |
| 1.80 – 1.90 | 0.030 | ~33 |
| 1.90 – 2.00 | 0.033 | ~30 |
| 2.00 – 2.20 | 0.040 | ~25 |
| 2.20 – 2.40 | 0.050 | ~20 |
| 2.40 – 2.60 | 0.065 | ~15 |
| 2.60 – 2.80 | 0.080 | ~12 |
| 2.80 – 3.00 | 0.100 | ~10 |
Nominal trade approximations for well-made round melee. Actual weight varies with depth and make; the specification on each listing is authoritative.
How shapes are quoted
- Round brilliant
- Sized on diameter. The workhorse of pavé, halos and accent lines.
- Princess / square
- Sized on the square face measurement, corner to corner is larger — check your seat width.
- Baguette
- Quoted length × width. Straight and tapered run differently in channel work.
- Marquise / pear
- Quoted length × width; tip protection matters more than size tolerance.
- Oval
- Quoted length × width; matched pairs need both axes controlled.
Measuring before you order
- Measure the seat, not the old stone — worn stones read small.
- Use a loupe-grade gauge or digital calipers to 0.01 mm.
- For pavé runs, order a band (e.g. 1.30–1.40 mm) rather than a single number.
- For restoration, tell us the setting style; we sort for fit, not just size.
Still unsure which band to buy? Send us the seat measurement and we'll tell you what sorts to.