A karat measures how much pure gold is in a piece — here's exactly what it means and how it affects value.
Published September 3, 2026
A karat is a measure of how much pure gold is in a piece of jewelry or bullion, out of 24 total parts. 24 karat gold is 100% (technically 99.9%) pure gold. 14 karat gold is 14 parts gold and 10 parts other metal — 58.3% pure. The lower the karat, the less pure gold and the lower the melt value for the same weight.
Pure (24k) gold is very soft — too soft to hold up well in rings, chains, or bracelets worn every day. Jewelers alloy it with other metals like copper, silver, or zinc to make it more durable, which is why almost all gold jewelry is stamped with a karat lower than 24k rather than sold pure.
24k (99.9% pure) is used mainly for bars and coins. 18k (75%) has a richer color and more gold content, common in fine jewelry. 14k (58.3%) is the most common karat for everyday US jewelry, balancing durability and cost. 10k (41.7%) is the lowest purity that can legally be sold as gold in the US. See the full Gold Karat Chart for every common karat and its typical uses.
Melt value = weight in grams × karat purity (as a decimal) × the current gold price per gram. A higher karat means more gold content, so it’s worth more per gram — but a lower-karat piece isn’t worthless, it just has less pure gold in it. Use the Gold Calculator with your item’s weight and karat to get an exact number.
Karat (with a K) measures gold purity. Carat (with a C) is a completely different measurement, used for gemstone weight. See Karat vs Carat: What’s the Difference? for the full breakdown.
24 karat (24k) is the purest form of gold sold, at 99.9% gold. Anything stamped '24k' or '999' is considered pure gold.
Higher karat means more gold content and value, but also a softer, less durable metal. Many people choose 14k or 18k over 24k specifically because it holds up better to daily wear.
Look for a small stamp on the piece, usually reading something like 14K, 585, or 750 (purity marks are sometimes stamped as a 3-digit purity percentage instead of a karat number). If there's no visible stamp, a jeweler can test it for you.