Tools
Gold Karat Calculator
Convert between karat, fineness, and percentage. Calculate the pure gold content and value of jewelry or coins by karat.
Gold Karat Reference Table
Common gold karats with their fineness, purity percentage, and typical uses.
| Karat | Fineness | Purity | Common Uses |
|---|---|---|---|
| 24K | 999.9 | 99.99% | Investment bullion, gold bars, Canadian Maple Leaf |
| 22K | 916.7 | 91.67% | American Gold Eagle, Krugerrand, sovereign coins |
| 21K | 875.0 | 87.50% | Middle Eastern and South Asian jewelry |
| 18K | 750.0 | 75.00% | Fine jewelry, watches, European standard |
| 14K | 585.0 | 58.33% | Standard US jewelry, engagement rings, everyday wear |
| 10K | 417.0 | 41.67% | Budget jewelry, minimum legal gold in the US |
| 9K | 375.0 | 37.50% | Common in UK and Australia, affordable gold jewelry |
Frequently Asked Questions
What does karat mean in gold?
Karat (abbreviated K or kt) is a unit that measures the purity of gold. Pure gold is 24 karat, meaning 24 out of 24 parts are gold. An 18K piece contains 18 parts gold and 6 parts other metals such as copper, silver, or zinc. Karat should not be confused with carat, which is a unit of weight used for gemstones.
What is the difference between karat and fineness?
Karat expresses gold purity on a scale of 0 to 24, while fineness (also called millesimal fineness) expresses purity in parts per thousand. For example, 18K gold has a fineness of 750, meaning 750 out of 1,000 parts are pure gold. Both systems convey the same information in different formats.
Is 24K gold too soft for jewelry?
Yes, 24K gold is very soft and prone to scratching, bending, and denting. That is why most jewelry uses lower karat alloys. In the United States, 14K is the most popular choice for everyday jewelry, while 18K is favored for fine jewelry in Europe and Asia. The added metals increase durability while retaining the appearance of gold.
What is the minimum karat to be legally called gold in the US?
In the United States, an item must be at least 10 karat (41.7% pure gold) to be legally marketed and sold as gold jewelry. In the United Kingdom and Australia, the minimum is 9 karat (37.5%). These standards are enforced by the Federal Trade Commission in the US.
How do I find the karat of my gold jewelry?
Most gold jewelry is stamped with a hallmark indicating its karat. Look for markings such as 10K, 14K, 18K, 22K, or 24K. You may also see fineness stamps like 585 (14K), 750 (18K), or 999 (24K). If there is no stamp, a jeweler can test the purity using acid testing, electronic testing, or X-ray fluorescence (XRF) analysis.