24K · 22K · 18K purity converter
See how much pure gold a piece holds, convert weight between purities, and value it at your own 24K rate.
Slide to any purity to see its rate.
Rate = purity × 24K rate. Enter the rate you know for the selected grade; its pure 24K rate is that rate ÷ the grade's fineness (24K = 1000, 22K = 916, 18K = 750). Each grade's rate is then its fineness × the 24K rate, and any purity's rate is its percentage × the 24K rate.
Rate by grade
Optional — enter today's rate per gram of pure (24K) gold to see value.
Pure gold = weight × karat ÷ 24. Hallmarks: 24K = 999, 22K = 916, 18K = 750, 14K = 583.
Pure gold content
Same pure gold, at other purities
What 24K, 22K and 18K mean
Karat measures purity in twenty-fourths. 24K is effectively pure gold (99.9%). 22K is 22/24 ≈ 91.7% pure, 18K is 75%, and 14K is 58.3%. The remainder is alloy — copper, silver or zinc — added for hardness and colour.
Those fractions are exactly what hallmark numbers mean: 916 marks 22K (91.6%), 750 marks 18K (75%) and 585 marks 14K (58.5%).
BIS hallmarking in India
Hallmarked gold jewellery in India carries three stamps: the BIS logo, a purity mark such as 916 or 750, and a six-character alphanumeric HUID unique to the piece. Together they certify the stamped purity.
When buying, match the hallmark to the rate you are charged — a 22K (916) piece should be priced from the 22K rate, not the 24K board rate. The converter above shows what a piece is worth at any purity from your own 24K rate.
Frequently asked questions
What does 916 gold mean?
916 is the hallmark for 22-karat gold — 22/24 ≈ 91.6% pure. Likewise 750 marks 18K (75%) and 585 marks 14K (58.5%).
Which gold purity is best for daily wear?
22K (916) is the traditional choice for Assamese jewellery and holds the most gold value. 18K is harder, resists scratches and grips stones more securely, so it is common for daily-wear and stone-set designs.
How much pure gold is in 10 grams of 22K jewellery?
10 g × 22/24 ≈ 9.17 g of pure gold. The converter above works this out for any weight and purity.
Why is 24K gold rarely used for jewellery?
Pure gold is soft — it bends and scratches with daily wear — so 24K is mostly kept for coins and bars while jewellery is made in 22K, 18K or 14K.