Gold Purity Chart: Karat, Fineness and Percent Explained

Gold purity chart at a glance

Here is the simple gold purity chart most Indian buyers need. 24K is about 99.9 percent gold, marked as 999 or 995 for bullion. 22K is 91.6 percent, marked 916. 18K is 75 percent, marked 750. 14K is about 58.5 percent, marked 585. The fineness number is parts of gold per thousand, and the BIS hallmark shows karat and fineness together, such as 22K916.

Understanding this gold purity chart lets you read hallmarks instantly, compare prices across karats and estimate how much fine gold you actually own. It also helps you check that the rate on your bill matches the purity of the piece.

Below, we explain how karat and fineness relate, how to calculate fine gold content, and why the same jewellery design can be offered in several purities.

You do not need to memorise complicated tables. Most jewellery sold in India falls into three grades: 22K for traditional pieces, 18K for diamond and contemporary jewellery, and 14K for lightweight and budget-friendly designs. Bullion coins and bars are usually 24K. Remembering these four, with their fineness numbers, covers almost every shopping situation you will encounter.

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Karat: purity out of 24

Karat expresses purity as parts of gold out of 24. 24 karat is pure gold, 22 karat is 22 parts gold and 2 parts other metals, 18 karat is 18 parts gold and 6 parts alloy, and 14 karat is 14 parts gold and 10 parts alloy.

To convert karat to percentage, divide the karat by 24 and multiply by 100. 22 divided by 24 is 0.9167, so 22K is about 91.67 percent gold. 18 divided by 24 is 0.75, so 18K is 75 percent. 14 divided by 24 is 0.583, so 14K is about 58.3 percent.

Note that karat for gold is different from carat for diamonds and gemstones. Carat measures weight, where one carat equals 0.2 grams.

It also helps to know that the alloy portion is not wasted. The copper, silver, zinc or palladium in lower karats gives strength, colour and wearability. Different recipes produce yellow, rose and white gold at the same karat. So while the percentage tells you how much gold you own, the alloy decides how the piece looks and wears.

Fineness: purity per thousand

Fineness expresses purity in parts per thousand. A 916 piece has 916 parts gold per 1,000, which is 91.6 percent. A 750 piece has 75 percent gold. A 585 piece has 58.5 percent gold. Bullion may be 995 or 999.

Fineness numbers used in hallmarking are standardised. 585 for 14K is slightly higher than the pure mathematical 583, reflecting a defined standard that ensures a minimum gold content. Similarly, 916 is the standard fineness for 22K.

Because fineness is precise, it is the number to focus on when calculating value. The BIS hallmark shows both the karat and fineness, removing any ambiguity.

When reading older jewellery, you may see a fineness number stamped without the BIS logo or HUID. Such stamps were applied by jewellers themselves and were not always independently verified. Treat them as indicators rather than proof. Testing by XRF or at a hallmarking centre can confirm the actual purity before exchange or resale.

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How to calculate fine gold in your jewellery

Multiply the net weight of the gold by the fineness and divide by 1,000. For example, a chain with a net weight of 10 grams at 916 fineness contains 10 times 916 divided by 1,000, which is 9.16 grams of fine gold. The same weight at 750 contains 7.5 grams; at 585, 5.85 grams.

Use net weight, not gross weight. If a pendant weighs 5 grams in total but has 0.5 grams of stones, the net gold weight is 4.5 grams. At 750 fineness, that is about 3.375 grams of fine gold.

Knowing your fine gold content helps when comparing exchange offers or estimating value over time. Jewellers typically value old gold on fine gold content after their deductions.

Here is another quick example. A pair of 18K diamond earrings with a gross weight of 4 grams and stone weight of 0.4 grams has a net gold weight of 3.6 grams. At 750 fineness, that is 2.7 grams of fine gold. This calculation shows how stones and lower karat both reduce the fine gold content in diamond jewellery.

Keep a small calculator app handy while shopping, and do these calculations as you compare pieces. The numbers quickly reveal which option gives you more gold for your money.

Other purity grades you may see

Besides 24K, 22K, 18K and 14K, BIS standards include additional grades for gold jewellery and artefacts, such as 20K and 23K, which are used less commonly in mainstream retail. If you come across them, the hallmark will show the karat with its corresponding fineness.

International markets also use 10K and 9K, which contain even less gold. These are more common abroad for fashion-oriented fine jewellery and may not be offered by Indian jewellers.

If you see an unfamiliar purity on a piece, check the hallmark carefully and verify the HUID in the BIS Care app.

Purity standards can be updated by authorities from time to time. If you are buying an unusual grade, check the latest information on the BIS website. For mainstream purchases, the core grades of 22K, 18K and 14K remain the most widely available and understood across India.

Why the same design comes in different karats

Diamond and lab-grown diamond brands often offer the same design in 14K and 18K, letting you choose between lower price and higher gold value. Traditional jewellers may offer bangles and chains in 22K and 18K for similar reasons.

The colour also changes. 22K is the richest yellow, 18K is softer, and 14K is paler still. Rose and white gold are mostly available in 18K and 14K.

Durability rises as karat falls. Lower karats resist scratches and bending better, which suits daily wear and delicate stone settings.

For gifting, the chart helps too. If you want a gift to carry more value, choose 22K for plain designs. If you want a durable everyday piece with diamonds, 18K or 14K makes sense. Knowing the trade-offs lets you match the purity to the recipient's lifestyle and the meaning of the occasion.

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Matching purity to rate and bill

Jewellers publish rates for different purities. The rate applied on your bill should match the purity on the hallmark. Charging a 22K rate for an 18K piece is an error you can catch using the chart.

Your bill should state the purity alongside the net weight. Check both before paying. If anything is unclear, ask the jeweller to explain the calculation using the fineness and net weight.

This habit protects you against honest mistakes and makes comparing offers across stores straightforward.

When rates are displayed at a store, they often show 24K and 22K prominently, and 18K separately. If a store lists only 24K, ask how they calculate rates for 22K and 18K. Some derive them using the fineness ratio, others publish their own figures. Understanding the method helps you check the bill accurately.

If you are buying a set where pieces are in different purities, such as a 22K necklace with 18K diamond earrings, check that each line on the bill uses the correct rate. Mixed-purity sets are common, and a careful look at each line ensures every piece is priced accurately according to its own fineness.

Save this chart

Remember the four key numbers: 999 or 995 for 24K bullion, 916 for 22K, 750 for 18K and 585 for 14K. Combine them with net weight to know exactly how much gold you own.

Always look for the BIS logo, purity grade and HUID together, verify them in the app and keep the invoice. With this chart in mind, every hallmark and every bill becomes easy to read.

Finally, share this chart with family members. Many buyers know their jewellery is 22K but have never connected it to 916, or never realised that 18K means 75 percent gold. A shared understanding makes family decisions about buying, exchanging and gifting much easier.

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