Gold karats: what 24K, 18K and 14K mean and how to tell them apart
A karat tells you how much pure gold a piece contains. Understanding it is the first step to knowing what a piece of jewelry or a bar is worth.
What is a karat?
Pure gold is too soft for most uses, so it is alloyed with other metals such as silver, copper, zinc or palladium. The karat (K) measures how much of that alloy is gold. The scale runs from 0 to 24: 24K gold is fine gold, and an 18K piece contains 18 parts gold out of 24, or 75%.
Purity is also expressed as fineness in parts per thousand. An 18K piece is stamped 750, meaning 750 parts gold per 1,000.
Karat and purity table
| Karat | Fineness | Pure gold | Typical use |
|---|---|---|---|
| 24K | 999 | 99.9% | Bars and bullion coins |
| 23K | 958 | 95.8% | Traditional jewelry in Asia |
| 22K | 916 | 91.6% | Jewelry in India and the Middle East, coins |
| 21K | 875 | 87.5% | Jewelry in the Middle East and parts of Latin America |
| 18K | 750 | 75.0% | Fine jewelry in Europe and Latin America |
| 14K | 585 | 58.5% | The most common jewelry standard in the US |
| 12K | 500 | 50.0% | Budget jewelry |
| 10K | 417 | 41.7% | Durable rings and everyday jewelry (US minimum) |
| 9K | 375 | 37.5% | Jewelry in the UK |
| 8K | 333 | 33.3% | Low-cost jewelry |
How is the price of each karat calculated?
Multiply the fine gold price by the purity. If a gram of 24K is worth $100, a gram of 18K is worth $75 and a gram of 14K is worth $58.50. On our home page you can pick any karat and see its live price.
How to identify the karat of a piece
1. Look for the hallmark
Most jewelry has its purity stamped somewhere discreet: inside a ring, on a chain's clasp or on the back of a pendant. It may appear in karats (18K, 14K) or fineness (750, 585). A hallmark is not an absolute guarantee, but it is the starting point.
2. Acid and touchstone test
The jeweler rubs the piece on a dark stone and applies acids of different strengths. The way the streak reacts indicates the karat. It is quick and cheap, but depends on the tester's experience.
3. X-ray fluorescence (XRF)
A device analyzes the surface without damaging the piece and shows its composition in seconds. Professional buyers use it widely. Its limitation is that it only reads the surface, so a plated piece can give a misleading result.
4. Fire assay
The most accurate method, used by refineries and laboratories. A small sample is melted and the gold is separated from other metals. It destroys the sample, so it is mainly used for bars, doré and large lots.
Tip: if you are selling, ask for the test to be done in front of you and to see the result. With the karat and weight you can calculate the exact value with our calculator.