24K, 22K, 21K, 18K — What Gold Karat Actually Means

Karat is one of the few things in the gold market that is genuinely simple, and it gets over-explained constantly. Here is the whole idea in one sentence: karat is a fraction out of 24.

22 karat means 22 parts gold to 2 parts something else. 18 karat means 18 parts gold to 6 parts something else. That is it. Everything else — pricing, hallmarks, why certain countries prefer certain grades — follows from that one fact.

The purity table

The hallmark numbers are just the purity written as parts per thousand. A "916" stamp means 916 parts gold out of 1,000 — which is 22 karat. Once you know that, hallmarks stop being a code.

Why the price difference is exactly proportional

Because purity is a straightforward fraction, so is the value. 22K gold contains 91.67% as much gold as 24K by weight, so a gram of it is worth 91.67% of a gram of 24K — no more, no less.

This means you can check any quoted karat price in your head. If 24K is quoted at 10,000 per gram, then:

• 22K should be about 9,167
• 21K should be about 8,750
• 18K should be 7,500

If a shop's 22K price is much further below its 24K price than that ratio implies, they are quoting you a below-market rate for your metal. If it is above, something else — usually making charges — has been folded into the "rate".

What the other parts actually are

The non-gold portion is alloy: usually copper, silver, zinc, or nickel and palladium in white gold. It exists for a practical reason. Pure gold is soft. It scratches, bends and wears down. A 24K ring worn daily will visibly deform.

Alloy makes gold hard enough to hold a shape, hold a stone, and survive being worn. It also changes the colour:

• Copper-heavy alloy gives the warm reddish tone of rose gold
• Silver and palladium shift it paler, towards white gold
• Balanced alloy produces the standard yellow most jewellery uses

So the choice of karat is a trade-off between purity and durability, not simply "more is better".

Why different countries settled on different grades

This is cultural and economic history, not metallurgy.

In South Asia and the Gulf, gold jewellery has traditionally been a store of wealth as much as an ornament — something a family can sell when needed. Higher purity means more of the price is recoverable metal, so 22K became the standard. It is high enough to retain value and just hard enough to wear.

In Europe and the United States, jewellery has been bought primarily as adornment. Durability and design mattered more than resale, so 18K and 14K dominate — harder, cheaper, and better at holding gemstones.

In Thailand, 96.5% purity became the trade standard, which sits between 23K and 24K. In Vietnam and China, near-pure 24K jewellery is common and often sold close to bullion pricing.

None of these is more correct than the others. They are answers to different questions.

Which should you actually buy?

It depends entirely on what you want the gold to do.

If you are buying to hold value: higher purity, and preferably not jewellery at all. Coins and bars carry far lower premiums than crafted pieces, and a 24K coin's resale is close to its metal value. 22K jewellery is the traditional compromise where jewellery is the cultural expectation.

If you are buying to wear daily: 18K or 14K. A daily-wear 24K ring will lose its shape. This is not a compromise on value so much as a recognition that the piece needs to survive.

If you are buying gem-set jewellery: 18K or below, because softer settings do not hold stones securely.

You can compare the value of the same weight at every purity, in any currency, with our karat calculator.