Ring Size Conversion Chart
| US Size | UK Size | EU Size | Diameter (mm) | Circumference (mm) |
|---|
| 5 | J 1/2 | 49 | 15.7 | 49.3 |
| 6 | L 1/2 | 52 | 16.5 | 51.8 |
| 7 | N 1/2 | 54 | 17.3 | 54.4 |
| 8 | P 1/2 | 57 | 18.1 | 57.0 |
| 9 | R 1/2 | 59 | 18.9 | 59.5 |
| 10 | T 1/2 | 62 | 19.8 | 62.1 |
Diamond Carat Size Reference
| Carats | Weight (mg) | Round Diameter |
|---|
| 0.25 | 50 | ~4.1 mm |
| 0.50 | 100 | ~5.2 mm |
| 1.00 | 200 | ~6.5 mm |
| 1.50 | 300 | ~7.4 mm |
| 2.00 | 400 | ~8.2 mm |
Gold Karat Purity
| Karat | Gold % | Fineness | Common Use |
|---|
| 24K | 99.9% | 999 | Investment bars, coins |
| 22K | 91.7% | 917 | Indian, Middle Eastern jewelry |
| 18K | 75.0% | 750 | Fine jewelry (European) |
| 14K | 58.3% | 585 | US jewelry standard |
| 10K | 41.7% | 417 | Budget jewelry (US minimum) |
Precious Metal Weights
| Unit | Grams | Troy Oz |
|---|
| 1 grain | 0.0648 | 0.00208 |
| 1 pennyweight (dwt) | 1.5552 | 0.05 |
| 1 carat | 0.2 | 0.00643 |
| 1 troy ounce | 31.1035 | 1 |
| 1 troy pound | 373.242 | 12 |
Necklace and Chain Lengths
| Style | Inches | Centimeters |
|---|
| Collar | 14" | 35.6 cm |
| Choker | 16" | 40.6 cm |
| Princess | 18" | 45.7 cm |
| Matinee | 20-24" | 50.8-61 cm |
| Opera | 28-36" | 71-91 cm |
Convert measurements with our weight and length converters.