The basics
24K, 22K, 21K, 18K, 14K and 9K explained: purity, uses and which karat to buy
A karat is the share of pure gold in a piece out of 24 parts. We explain what each karat means, why countries favour different karats, how purity drives price, hardness, colour and resale value, and which karat suits saving and which suits wearing.
24K, 22K, 21K, 18K, 14K and 9K explained
The word "karat" comes up in every conversation about gold, yet many people buy and sell without knowing exactly what it measures, why 18K costs less than 24K, or why India and the Gulf favour 22K while Egypt prefers 21K and Europe and America buy 18K and 14K. This article explains the karat system from the ground up, the effect of each karat on price, hardness and colour, and how to choose the right karat for what you want from the gold.
What a karat is: 24 parts
The karat system divides any gold alloy into 24 parts; the karat is the number of those parts that are gold, the rest being other metals (copper, silver, zinc, palladium and others). 24K is practically all gold; 18K is 18 parts gold and 6 parts other metals; 14K is 14 parts gold and 10 parts other metals. Purity follows: karat ÷ 24.
| Karat | Purity | Fineness mark | Typical use |
|---|---|---|---|
| 24K | 99.9% and above | 999 or 999.9 | Bars and investment coins |
| 22K | 91.67% | 916 | Jewellery in India, Pakistan and the Gulf; some coins (the Sovereign, the Krugerrand) |
| 21K | 87.5% | 875 | Jewellery in Egypt, the Levant and the Gulf |
| 18K | 75% | 750 | Fine jewellery, Italian designs, stone-set pieces |
| 14K | 58.3% | 585 | Everyday jewellery in the United States and Europe |
| 10K / 9K | 41.7% / 37.5% | 417 / 375 | The budget end: the US legal minimum (10K) and the UK's most common fineness (9ct) |
The number stamped on a piece (750, 585, 375) is the purity in parts per thousand and corresponds to the karat; it is the first thing to look for in a hallmark. In the UK the word is spelt "carat" and abbreviated "ct"; the meaning is identical.
Why jewellery is not made of 24K
Pure gold is a very soft metal: a 24K ring bends, scratches and loses its shape with daily wear. Adding copper and silver hardens the alloy enough for fine work and for holding stones. So 24K is kept for bars and coins that are not worn, and jewellery is made of 22K, 21K, 18K or 14K according to each market's taste. The lower the karat, the harder the piece, the lower the price, and the less gold you get back when you sell.
Why countries favour different karats
- India and Pakistan: 22K (916) is the standard for jewellery because gold is bought as savings and dowry as much as adornment; 24K for coins and bars.
- Egypt and the Levant: 21K has been the norm for decades, a balance of purity and durability with the widest resale market.
- Saudi Arabia and the Gulf: 21K and 22K for traditional heavy pieces, 18K for modern designs.
- The United States: 14K is the most common jewellery karat, 10K the legal minimum, 18K for fine jewellery.
- The United Kingdom and Europe: 9ct and 18ct in Britain, 14K and 18K on the continent, because jewellery is bought for design rather than saving and a lower karat allows larger pieces at a given price.
- Turkey: 22K for the gram, quarter, half and full coins, 14K and 18K for jewellery.
Social habit explains the pattern: where gold is bought to save, karats are high; where it is bought to wear, they are lower.
How the karat drives the price
The gram price is proportional to purity. Today (November 7, 2026) a gram of 24K is $130.92, of 18K $98.19 and of 14K $76.37; in sterling £98.02, £73.52 and £36.76 for 9ct. But watch the making charge: a delicate 18K piece can carry a higher making charge than a plain 22K piece, so the final prices can be closer than the purity gap suggests. If you are buying to save, what matters is the pure gold you pay for, not the ticket price.
How the karat affects colour
Colour comes from the added metals, not from the karat alone. Pure gold is a warm yellow. More copper gives rose gold; silver, palladium or nickel gives white gold, usually plated with rhodium to look whiter. Two 18K rings can therefore be completely different colours, and an 18K white-gold ring contains exactly 75% gold like a yellow one and is bought as scrap at the same value once the plating is removed.
How the karat affects resale
Scrap is bought by weight of pure gold: a 10 g piece of 14K contains 5.83 g of gold, a 10 g piece of 22K contains 9.17 g. The making charge is lost in both cases, but the deduction on lower karats is usually larger, because the buyer has to refine a smaller share of gold out of a larger mass of alloy. The rule: the higher the karat, the closer the selling price to the buying price.
Karat, hardness and wear over time
The higher the karat, the softer the metal: a 22K ring scratches and loses the crispness of its edges faster than an 18K one, and a thin 21K chain breaks sooner than the same chain in 18K. That is why pieces worn daily (rings, thin bracelets) are made in lower karats or in thicker designs, and heavy occasion pieces in 21K and 22K. Wear also removes a little metal over the years, which shows up as a small weight difference when the piece is weighed for sale.
Which karat to choose
- For pure saving: 24K in a bar or coin; negligible making cost, no VAT in many countries, and the simplest to price when selling.
- For saving you can wear: 21K or 22K in heavy, simple pieces; low making charges and a high gold content.
- For design and daily wear: 18K is harder, holds stones and comes in more colours, but expect to lose a larger share of its price when you sell.
- Avoid buying 14K or lower as savings: half or more of its price is other metals and workmanship.
Reading the karat on the invoice
A proper invoice states for each piece: the weight in grams to two decimals, the karat (18K) or fineness (750), the day's gram rate for that karat, the making charge and the tax. Compare the stated karat with the hallmark struck on the piece; any mismatch is reason enough to hand it back. When you sell, the invoice is what stops a buyer from "testing" the karat on his own terms and deducting what he likes.
How to confirm the karat
Look for the hallmark (750, 585, 916) with the maker's or assay mark and compare it with the invoice. In the UK the Assay Office mark is compulsory; in India the BIS mark with its HUID; in Egypt the government stamp; in Kuwait and Bahrain a compulsory state hallmark. When in doubt ask for an XRF test, which many shops can run in seconds without scratching the piece. The full guide: how to tell real gold.
Frequently asked questions
Is 22K better than 18K?
For saving, yes: more pure gold and a smaller deduction when you sell. For design, daily wear and stone settings, 18K is harder and more varied.
Is 24K jewellery made at all?
Rarely, mainly in some Asian markets; it is too soft for daily wear and is normally kept for bars and coins.
What does 750 stamped on a ring mean?
750 parts per thousand gold, that is 75%, which is 18K.
Is white gold a lower karat than yellow?
No; the colour comes from the added metals, and white and yellow pieces can share the same karat and purity.