A karat is one part in 24. Pure gold is 24 karat. 14K gold is 14 parts gold and 10 parts other metals, such as silver, copper, nickel or zinc, which make it harder and change its color.
Karat to purity
The fineness stamp is the gold percentage in thousandths: 999 for 24K, 916 for 22K, 750 for 18K, 585 for 14K and 417 for 10K. US 14K is stamped 585 rather than 583 because makers alloy slightly above the minimum.
How karat affects value
Value scales directly with purity. A gram of 18K holds 75% gold, almost twice the gold in a gram of 10K. That’s why the karat matters as much as the weight when you sell.
White, rose and yellow gold
Color comes from the other metals, not the gold. 14K white gold and 14K yellow gold contain the same amount of gold and are worth the same per gram.
Today’s value per gram
See the live table on our gold price today page, or open the page for a specific karat: 24K, 22K, 18K, 14K and 10K.