080 or 3 mm: 16" - 30" Inch Between 6.4 grams and 11.6 grams 100 or 4 mm: 16" - 30" Inch Between 9.0 grams and 15.3 grams 120 or 5 mm: 16" - 30" Inch Between 12.0 grams and 22.3 grams 150 or 6 mm: 18" - 30" Inch Between 21.5 grams and 35.8 grams 180 or 7 mm: 20" - 30" Inch Between 31.8 grams and 49.0 gram. 220 or 8 mm: 20" - 30" Inch Between 49.1 grams and 72.3 gram. 250 or 9 mm: 22" - 30" Between 62.7 and 88.7 grams 300 or 11 mm.
24", 30" Inch Between 113.0 grams and 125.3 grams. We suggest Necklace lengths 16"-20" for Boys, and 22"-30" inch for Men. All weights and width are approximate and may vary even in chains of the same width and.