Bead Types Ref
About Bead Types
What this tool does
Jewelry tools convert between carats, grams, and millimeters, determine ring sizes across international standards, calculate gold purity (karat to fineness), evaluate the 4Cs of diamonds, and estimate metal density for casting.
Why use this tool
Jewelers and buyers need precise conversions. Knowing the exact gram weight of a 1.5-carat diamond, or the gold content in 18K vs. 14K, informs pricing and design decisions. These tools provide instant, accurate answers.
How it works
Carat-to-gram conversion uses the fixed ratio 1 ct = 0.2 g. Ring-size conversion maps circumference in mm to lettered or numbered systems (US, UK, EU, JP). Gold karat to fineness divides by 24 (18K = 75% gold).
Pro tip
Ring size varies with temperature and time of day. For the most accurate measurement, size the finger in the afternoon when hands are warmest and slightly swollen, not first thing in the morning.
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