Despite sounding identical, karat and carat measure completely different things.
Karat (K or kt) — Gold Purity
| Karat | Gold Percentage | Common Use |
|---|---|---|
| 24K | 99.9%+ | Investment bullion |
| 22K | 91.67% | American Eagle, Krugerrand |
| 18K | 75% | Fine jewelry |
| 14K | 58.3% | Everyday jewelry |
| 10K | 41.7% | Budget jewelry (minimum legal "gold" in U.S.) |
Carat (ct) — Gemstone Weight
Carat measures the weight of gemstones. One carat equals 200 milligrams (0.2 grams). A 5-carat diamond weighs 1 gram.
The Takeaway
When discussing gold investments, always use "karat." When discussing diamonds or gemstones, use "carat."