Gold Karats and Purity Explained

The karat scale

The word comes from the carob seed once used as a counterweight; by the Middle Ages a 'karat' had become a 24th share of a gold coin's weight. Today the scale is fixed: karat ÷ 24 = gold fraction. 21k is 21 ÷ 24 = 87.5 %, 9k is 9 ÷ 24 = 37.5 %.

Do not confuse karat (gold purity) with carat (gemstone weight, 0.2 g). In British English both are often written 'carat', which is why UK stamps read 9ct or 18ct.

Price per gram by karat

Because only the gold content has market value, the price of a gram of karat gold is linear in purity. If 24k costs $135 per gram, 22k is about $124, 21k $118, 18k $101, 14k $79, 10k $56 and 9k $51. The live table on this page shows today's exact numbers.

Retail jewellery costs more than this because of making charges, design and dealer margin. In India and the Gulf, making charges are quoted separately per gram or as a percentage; in Western jewellery stores they are built into the tag price, which can be two to four times the gold value.

What the rest of the alloy is

The non-gold part is chosen for colour and strength. Yellow gold uses silver and copper. Rose gold uses more copper. White gold uses palladium or nickel and is usually rhodium-plated for a bright finish. Green gold has extra silver. These alloy metals have little value in scrap pricing — buyers pay for the gold content only.

Durability and everyday wear

Pure gold is soft. 24k scratches and bends easily, which is why it's used for bullion and investment jewellery more than for rings. 22k and 21k are traditional in South Asia and the Middle East — rich colour, still soft enough to dent. 18k is the European fine-jewellery standard and a good balance of colour and strength. 14k is the most popular choice in the US for engagement rings and everyday pieces because it resists wear well. 10k and 9k are the hardest and cheapest, but tarnish more over time because of the higher base-metal content.

Which karat is best?

For investment and resale value, higher karat is better: you pay for gold, and when you sell you get paid for gold, with fewer alloy deductions. For daily wear, 14k or 18k lasts longer. For gifts in India, Pakistan, the Gulf and much of Southeast Asia, 22k or 21k is the expected standard and carries the best buy-back terms at local jewellers.

When comparing offers, always reduce them to price per gram of pure gold: divide the price per gram by the purity. A 14k ring at $95/g is $162 per gram of fine gold — compare that with the 24k spot price to see the real markup.

Countries and their usual karats

USA and Canada: 10k, 14k, 18k. UK and Ireland: 9ct, 18ct, 22ct. Continental Europe: 14k (585) and 18k (750); 8k (333) in Germany. India and Pakistan: 22k, with 18k growing for diamond jewellery. UAE, Saudi Arabia, Kuwait, Qatar: 21k and 22k. China and Hong Kong: 24k 'chuk kam' (999). Turkey: 22k for bracelets and coins, 14k for fashion jewellery.

Converting between karat, fineness and percentage

Three systems describe the same thing. Karat is parts per 24, fineness is parts per 1,000, and percentage is parts per 100. To convert karat to fineness multiply by 41.667: 18 × 41.667 = 750. To convert fineness to karat divide by 41.667: 585 ÷ 41.667 ≈ 14. To convert fineness to percentage divide by 10. The gold purity calculator does all three at once, and adds the live price for the purity you enter.

A quick mental check when you see a price tag: 18k is three quarters gold, 14k is a little under 60 %, 10k is a little over 40 %. If a seller quotes a 14k item at nearly the 24k price per gram, the gram price includes a large markup for design or brand, which you will not get back when selling it as scrap. Likewise, if a buyer offers you the 10k rate for a piece clearly stamped 750, ask them to test it again in front of you.

Odd numbers appear because standards were rounded at different times. 14k is mathematically 583.3 parts per thousand, but most countries now set the minimum at 585 so that every legal 14k piece contains at least 14 full karats. 22k is 916.7, normally stamped 916; 21k is exactly 875.

How karat affects the price you pay and receive

When you buy jewellery, the gold value is only part of the price. Suppose 22k gold costs $124 per gram and a 10 g bangle is offered with a 12 % making charge: the gold is $1,240 and the making charge adds $149, before any sales tax. In India, 3 % GST applies on the total. When you later sell the same bangle as scrap, you get paid for the gold content only, minus the buyer's margin, so the making charge is not recovered.

That's why buyers who care about resale favour higher karats with low making charges, such as plain 22k chains or 24k coins, and why scrap values in the per-karat pages are always below retail tag prices. For gifts and everyday wear, the extra durability of 14k or 18k may justify the higher proportion of your money going into craftsmanship rather than metal.