Karat
/KAIR-ut/
Definition
A unit of measurement indicating the purity of gold in an alloy, expressed on a scale of 24. Pure gold is 24 karat (24k); 18k gold is 75% pure gold.
Karat tells you how much actual gold is in the alloy. The scale runs to 24 parts. Pure gold is 24k at 99.9%. Everything else is a fraction of that. 22k is 91.7% gold. 18k is 75%. 14k is 58.3%. 10k is 41.7%. 9k, common in the UK, is 37.5%. At a spot price of about $2,847 per troy ounce (August 2026), that works out to roughly $91.50 per gram for pure gold content. Scale down by purity: 18k runs about $68.60/g, 14k about $53.30/g, 10k about $38.15/g. These are melt values. Retail jewelry adds labor, design, brand markup, and often 2-4x over metal cost. Do not confuse karat with carat. Karat measures gold purity. Carat measures gemstone weight. One carat equals 0.2 grams. Same word family, completely different jobs. I still see estate pieces where a buyer assumed the "18" stamped inside meant 18 carats of diamond. It meant 18k gold. Different measurement entirely. Market preferences split by region. The US retail market runs on 14k. Harder alloy, holds up to daily wear, keeps price accessible. Europe and much of Asia default to 18k or 22k. Richer yellow color, higher gold content, more prestige in those markets. India and the Middle East often push 22k for ceremonial gold. Reading stamps takes 10 seconds once you know the codes. Look inside the shank, on the clasp, or on the tag. Common marks: "14K," "585" (58.5% gold, the European equivalent of 14k), "750" for 18k, "916" for 22k, "999" for near-pure gold. A "KP" suffix means karat plumb, guaranteed minimum purity. If you see "GF" or "GP," that is gold filled or gold plated. Not solid karat gold. Higher karat is not automatically better. It is softer, scratches faster, and costs more. For a ring you wear every day, 14k is the practical sweet spot in the US. For a special-occasion necklace, 18k makes sense.
Usage in the Trade
Karat is used by jewelers, consumers, and appraisers to describe and evaluate gold jewelry. It appears on hallmarks and stamps inside rings, on clasps, and on jewelry tags.
Examples
A 5-gram 14k gold wedding band contains about 2.9 grams of pure gold. At $91.50/g pure, the melt value is roughly $265. Retail price for a simple band: $450-$800 depending on width and finish.
An 18k gold chain from Italy stamped "750" weighs 12 grams. Pure gold content: 9 grams. Melt value around $823. Retail at a US boutique: $1,400-$2,200 for the same chain.
A pawn shop offer on a 10k class ring weighing 8 grams might land at $220-$280 based on melt. The same ring at retail originally sold for $600-$900 because of design and markup, not just metal.
Frequently asked questions
What is the difference between karat and carat?
Karat (k or kt) measures gold purity on a 24-part scale. Carat (ct) measures gemstone weight, where one carat equals 0.2 grams. They sound alike but measure completely different things.
Is 14k or 18k gold better?
14k is harder and better for everyday rings and bracelets that take daily abuse. 18k has more gold (75% vs 58.3%), richer color, and higher melt value, but scratches more easily. Neither is universally better. It depends on how you wear it.
What karat gold is best for everyday wear?
14k gold is the standard for daily wear in the US because the alloy is harder and resists scratching better than 18k. For earrings or pendants that see less friction, 18k works fine.
How much is 24k gold per gram?
At a gold spot price of about $2,847 per troy ounce, 24k gold runs roughly $91.50 per gram for pure gold content. Prices move daily with the spot market.