Gold Purity Calculator — Karat to Fineness & BIS Hallmark Guide
24K Rate: ₹15,285.04/gConvert gold karat to fineness percentage and BIS hallmark code. Calculate the exact value per gram for every karat level (9K to 24K) using today's live rate. Essential guide for understanding BIS hallmarks (916, 750, 585) on your jewellery.
Gold Purity Calculator
All Gold Karats — BIS Hallmark & Live Value Table
| Karat | BIS Code | Purity % | Per Gram Today | Per 10g | Per Tola | Common Use |
|---|---|---|---|---|---|---|
| 24K | 999 | 99.9% | ₹15,285.04 | ₹1,52,850 | ₹1,78,282 | Bullion, coins |
| 23K | 958 | 95.8% | ₹14,648.16 | ₹1,46,482 | ₹1,70,853 | Industrial |
| 22K | 916 | 91.6% | ₹14,011.29 | ₹1,40,113 | ₹1,63,425 | Jewellery (India standard) |
| 21K | 875 | 87.5% | ₹13,374.41 | ₹1,33,744 | ₹1,55,996 | European jewellery |
| 20K | 833 | 83.3% | ₹12,737.53 | ₹1,27,375 | ₹1,48,568 | Mid-grade |
| 18K | 750 | 75.0% | ₹11,463.78 | ₹1,14,638 | ₹1,33,711 | Diamond setting, white gold |
| 17K | 708 | 70.8% | ₹10,826.90 | ₹1,08,269 | ₹1,26,283 | European standard |
| 14K | 585 | 58.5% | ₹8,916.27 | ₹89,163 | ₹1,03,998 | Western jewellery |
| 10K | 417 | 41.7% | ₹6,368.77 | ₹63,688 | ₹74,284 | Budget jewellery |
| 9K | 375 | 37.5% | ₹5,731.89 | ₹57,319 | ₹66,856 | UK 9ct jewellery |
How to Read BIS Hallmarks on Gold Jewellery
The 4 Components of a BIS Hallmark
- BIS Logo — A triangle enclosing the letters "BIS". Indicates the piece has been assayed at a BIS-authorised Assaying & Hallmarking Centre.
- Purity/Fineness Mark — A 3-digit number: 999 (24K), 958 (23K), 916 (22K), 875 (21K), 750 (18K), 585 (14K). This is the actual gold content in parts per thousand.
- Jeweller's Identification — A unique code assigned by BIS to the jeweller. You can verify it on the BIS Care app.
- HUID (Hallmark Unique Identification) — A 6-character alpha-numeric code unique to each jewellery piece. Introduced September 2021. Can be verified on the BIS Care app or at care.bis.gov.in.
Why 916 is the Most Common Hallmark in India
22K/916 gold strikes the optimal balance between purity and durability for the Indian jewellery market. Compared to 24K, it is harder and more resistant to scratching and bending — crucial for intricate Indian jewellery designs like Kundan, Meenakari, and temple jewellery.
Difference Between 22K Hallmarked and Ordinary 22K Gold
Both claim 22K purity, but hallmarked gold is independently verified by a BIS-authorised centre. Non-hallmarked jewellery may actually be 20K or lower despite being sold as 22K. Since June 2021, selling non-hallmarked jewellery above 2g is illegal in India.
FAQ — Gold Purity & Hallmarking
916 is the BIS hallmark code for 22K gold — it means 91.6% pure gold (22 parts gold out of 24). 22K/916 is the most common purity for gold jewellery in India. Today's 22K rate = ₹14,011.29/gram.
750 is the BIS hallmark code for 18K gold — 75% pure gold. 18K gold is commonly used in diamond jewellery and white gold pieces because it is harder and holds stones better than 22K.
999 (24K) gold is better for investment — it has the highest purity and best resale value. 916 (22K) is better for jewellery — it is more durable. For gold bars and coins, always buy 999 or 995 purity.
A BIS hallmark has 4 components: (1) BIS logo (triangle with "BIS"), (2) Purity/fineness mark (e.g. 916, 750), (3) Jeweller's identification number, (4) HUID — 6-digit alpha-numeric Hallmark Unique ID. Since Sep 2021, HUID is mandatory on all hallmarked gold jewellery.
Karat and carat mean the same thing for gold purity — 22K = 22 carat = 91.6% pure. "Carat" for gemstones is a weight unit (1 carat = 0.2g), while "karat" for gold always refers to purity. In India, both spellings are used interchangeably for gold.
You can use: (1) Acid test — nitric acid reacts differently with different purities, (2) Magnet test — pure gold is not magnetic, (3) Electronic gold tester (XRF analyser) — professional method at jewellers. The most reliable method is fire assay by a BIS-certified assaying centre.