Round brilliant black melee is chosen by the millimeter and weighed by the carat. This chart translates between the two, so you can plan a band, a halo or a pavé field before you order. Every size is calibrated to ±0.05mm and sorted by hand under the loupe.
How many stones, how much weight.
Pick a size, then enter a stone count or a total carat weight. The other fills in.
Estimates only. Actual weight is confirmed on the scale.
Each row is a calibrated size. The dot beside it shows that size relative to the others, so you can see where a 1.30mm ends and a 1.50mm begins. Select any row to load it into the estimator.
| Scale | Size | Range (mm) | Approx. ct / stoneCt each | Approx. stones / ctPer ct |
|---|---|---|---|---|
| 0.80mm | 0.75–0.85 | 0.0023 ct | 435 | |
| 0.90mm | 0.85–0.95 | 0.0029 ct | 345 | |
| 1.00mm | 0.95–1.05 | 0.0035 ct | 286 | |
| 1.10mm | 1.05–1.15 | 0.0041 ct | 244 | |
| 1.20mm | 1.15–1.25 | 0.0075 ct | 133 | |
| 1.30mm | 1.25–1.35 | 0.0086 ct | 116 | |
| 1.40mm | 1.35–1.45 | 0.0132 ct | 76 | |
| 1.50mm | 1.45–1.55 | 0.0155 ct | 65 | |
| 1.60mm | 1.55–1.65 | 0.0190 ct | 53 | |
| 1.70mm | 1.65–1.75 | 0.0228 ct | 44 | |
| 1.80mm | 1.75–1.85 | 0.0253 ct | 40 | |
| 1.90mm | 1.85–1.95 | 0.0288 ct | 35 | |
| 2.00mm | 1.95–2.05 | 0.0322 ct | 31 | |
| 2.10mm | 2.05–2.15 | 0.0362 ct | 28 | |
| 2.20mm | 2.15–2.25 | 0.0380 ct | 26 | |
| 2.30mm | 2.25–2.35 | 0.0425 ct | 24 | |
| 2.40mm | 2.35–2.45 | 0.0460 ct | 22 | |
| 2.50mm | 2.45–2.55 | 0.0590 ct | 17 | |
| 2.60mm | 2.55–2.65 | 0.0625 ct | 16 | |
| 2.70mm | 2.65–2.75 | 0.0690 ct | 14 | |
| 2.80mm | 2.75–2.85 | 0.0880 ct | 11 | |
| 2.90mm | 2.85–2.95 | 0.1100 ct | 9.1 | |
| 3.00mm | 2.95–3.05 | 0.1200 ct | 8.3 | |
| 3.10mm | 3.05–3.15 | 0.1300 ct | 7.7 | |
| 3.20mm | 3.15–3.25 | 0.1400 ct | 7.1 | |
| 3.30mm | 3.25–3.35 | 0.1600 ct | 6.2 | |
| 3.40mm | 3.35–3.45 | 0.1700 ct | 5.9 | |
| 3.50mm | 3.45–3.55 | 0.1900 ct | 5.3 | |
| 3.60mm | 3.55–3.65 | 0.2100 ct | 4.8 | |
| 3.70mm | 3.65–3.75 | 0.2250 ct | 4.4 | |
| 3.80mm | 3.75–3.85 | 0.2350 ct | 4.3 | |
| 3.90mm | 3.85–3.95 | 0.2500 ct | 4.0 | |
| 4.00mm | 3.95–4.05 | 0.2600 ct | 3.8 | |
| 4.10mm | 4.05–4.15 | 0.2800 ct | 3.6 | |
| 4.20mm | 4.15–4.25 | 0.3000 ct | 3.3 | |
| 4.30mm | 4.25–4.35 | 0.3200 ct | 3.1 | |
| 4.40mm | 4.35–4.45 | 0.3400 ct | 2.9 | |
| 4.50mm | 4.45–4.55 | 0.3600 ct | 2.8 | |
| 4.60mm | 4.55–4.65 | 0.4000 ct | 2.5 | |
| 4.70mm | 4.65–4.75 | 0.4300 ct | 2.3 | |
| 4.80mm | 4.75–4.85 | 0.4600 ct | 2.2 | |
| 4.90mm | 4.85–4.95 | 0.5000 ct | 2.0 | |
| 5.00mm | 4.95–5.05 | 0.5500 ct | 1.8 | |
| 5.10mm | 5.05–5.15 | 0.6000 ct | 1.7 |
*Counts are approximate, based on standard calibrated round brilliant black diamond melee, and vary with cutting proportions and size within the ±0.05mm tolerance. Scale dots show relative size, not actual size on screen.
Diameter is the spec
Settings are built around millimeters, not carats. Order to the seat size your setter or CAD calls for, then use the weight column to plan the budget.
Weight follows the make
Two natural stones of the same diameter can weigh differently. A deeper pavilion or a thicker girdle adds weight without adding spread. Counts here assume standard proportions.
Natural diamond, treated color
Every stone is a natural diamond, screened for natural origin before it ships. Black diamond melee is color treated to produce its even black body color unless a listing states natural color.
How melee is sold
Online orders are sold by the piece. Trade orders are priced per carat, with final weight and price confirmed upon ship. Melee is not available on trade memo.
Round brilliant black diamond melee, sorted by hand and screened for natural origin before it ships.
