Gold Purity Calculator & Karat Converter

916 means the gold is 91.6% pure, which equals 22 Karat. This is the most common purity for Indian gold jewelry. The number 916 is the millesimal fineness — parts of gold per 1000 parts of the alloy. BIS (Bureau of Indian Standards) hallmark with 916 guarantees the purity.

24K gold is 99.9% pure gold (999 fineness) — too soft for jewelry, used for coins and bars. 22K gold is 91.6% pure (916 fineness) — mixed with 8.4% other metals (copper, silver, zinc) for durability. 22K is the standard for Indian jewelry. 24K costs more per gram but 22K is more practical.

Professional methods: (1) Acid test — jeweler applies acid to a scratch mark, (2) XRF testing — non-destructive X-ray analysis, (3) Specific gravity test — compare weight in air vs water. DIY checks: (1) Magnet test — real gold isn't magnetic, (2) Ceramic test — real gold leaves a gold streak, not black. Always buy BIS hallmarked gold for guaranteed purity.

Yes, since June 2021, BIS hallmarking is mandatory for gold jewelry sold in India. The hallmark includes: (1) BIS logo, (2) Purity/fineness grade (e.g., 916), (3) 6-digit HUID (Hallmark Unique ID) that can be verified online at bis.gov.in. Jewelers must be BIS certified.

24K (999) is best for investment because: (1) Highest purity = highest resale value, (2) No deduction for alloy content, (3) Globally traded standard, (4) Available as coins/bars with no making charges. For jewelry, 22K (916) is standard in India as it balances purity with durability.

Divide the karat by 24 and multiply by 100. Formula: Purity % = (Karat ÷ 24) × 100. For example: 22K = (22/24) × 100 = 91.67%. For millesimal fineness: Fineness = (Karat ÷ 24) × 1000. So 22K = 916 fineness.