Karat Calculator
Convert between karats, fineness stamps, and purity percentages. See the gold content and live price for any karat using this free gold purity calculator.
Karat → Purity & Price
Fineness → Karat & Price
Gold Karat Reference Table
| Karat | Purity % | Fineness | Price/Gram | Price/Troy Oz |
|---|---|---|---|---|
| 24K | 100.0% | 999 | $152.29 | $4,736.66 |
| 22K | 91.7% | 916 | $139.62 | $4,342.53 |
| 21K | 87.5% | 875 | $133.26 | $4,144.99 |
| 20K | 83.3% | 833 | $126.91 | $3,947.45 |
| 18K | 75.0% | 750 | $114.23 | $3,552.85 |
| 14K | 58.3% | 585 | $88.84 | $2,763.17 |
| 12K | 50.0% | 500 | $76.15 | $2,368.57 |
| 10K | 41.7% | 417 | $63.46 | $1,973.96 |
| 9K | 37.5% | 375 | $57.11 | $1,776.42 |
| 8K | 33.3% | 333 | $50.72 | $1,577.46 |
See specific prices for 14K gold, 10K gold, and 18K gold. Or use the gold estimator to calculate melt value.
How the Karat System Works
The karat system divides gold purity into 24 parts. Pure gold is 24K—meaning all 24 parts are gold. When gold is alloyed with other metals to increase durability, the karat number decreases proportionally.
To calculate gold purity from karats: divide the karat number by 24. For example, 14K gold: 14 ÷ 24 = 0.583 = 58.3% pure gold. The remaining 41.7% is alloy metals like copper, silver, zinc, and nickel.
The karat system originated in medieval Europe as a way to measure gold purity. The number 24 was chosen because it divides evenly into many whole numbers, making it practical for ancient goldsmiths.
Common Fineness Stamps Explained
Fineness is an alternative way to express gold purity, used internationally. Instead of parts out of 24, fineness uses parts per thousand. This system is common on European, Asian, and Middle Eastern jewelry.
999 = 24K pure gold. 916 = 22K. 750 = 18K. 585 = 14K. 417 = 10K. 375 = 9K. 333 = 8K.
To convert fineness to karat: divide by 1000 and multiply by 24. For example: 585 ÷ 1000 × 24 = 14.04K ≈ 14K. This gold estimator and karat calculator handles these conversions automatically.
Karat vs Carat: What's the Difference?
Karat (K) measures gold purity—how many parts out of 24 are pure gold. Used exclusively for gold.
Carat (ct) measures gemstone weight. One carat equals 0.2 grams or 200 milligrams. Used for diamonds, rubies, sapphires, and other gemstones.
They sound the same and are often confused, but they measure entirely different things. A "2 carat 14K gold diamond ring" means the diamond weighs 0.4 grams and the gold setting is 58.3% pure gold. Our calculator handles gold value only—gemstone value must be appraised separately.