Metal that lasts
What Is a Karat in Gold? (Not a Carat)
Karat is a 24-part purity scale. 14k is 14/24 gold (58.3%). A carat is 200 mg of gemstone. Mixing them up is how people buy the wrong thing with confidence.
Updated 27 Aug 2026 · 6 min read · what is a karat in gold
The 24-part scale, in numbers you can use
Take the karat, divide by 24, multiply by 100. 22k is 91.6%. 18k is 75%. 14k is 58.3%. 12k is 50% and rarely sold as jewelry in the US. 10k is 41.7%. 9k is 37.5%. The rest of the alloy is what makes the metal hard enough to be a 2 mm band instead of a smear.
European stamps often skip the k and print millesimal fineness: 375, 417, 585, 750, 916, 999. That is the same information. A piece stamped 14k and 585 is repeating itself, not adding gold.
Karat is not quality, and it is not carat
Higher karat is more gold and a richer yellow, not a better chain. 18k prongs on a daily ring wear faster than 14k. 24k is for a 1 mm olive-leaf pendant you take off, or for bullion. Meanwhile a “1 carat gold ring” in a marketplace title is often a seller who cannot spell — or who wants you to think the ring contains a 1 ct diamond. For the UK-vs-US stamp map, use 9k versus 14k before you import a 375 band and expect a US shop to call it gold.
| Stamp | Karat | Gold % |
|---|---|---|
| 375 | 9k | 37.5% |
| 417 / 10k | 10k | 41.7% |
| 585 / 14k | 14k | 58.3% |
| 750 / 18k | 18k | 75% |
| 916 / 22k | 22k | 91.6% |
| 999 / 24k | 24k | ~99.9% |
Filled and plated still use karat numbers
14/20 GF means the gold layer is 14k and is 1/20 of the weight. “18k gold plated” means the film is 18k and the film might be 0.17 micron. The karat on plate describes the color of the paint, not the value of the object. Price the object by how the gold is attached, then by karat.
Questions, answered
- Is 14k real gold?
- Yes. 58.3% gold, legally sold as gold in the US. It is not 24k, and it does not need to be.
- Why do people write carat for gold?
- UK English often uses “carat” for both purity and gem weight. US jewelry uses karat for gold and carat for stones. Read the number: 18k is purity, 1.00 ct is a stone.
- Does higher karat mean less tarnish?
- Yellow gold above 14k does not really tarnish. Lower karat and rose alloys with more copper can mark skin. Sterling tarnishes; that is silver, not a karat problem.
