As a jeweler for over 50 years, one of the most common questions I hear is: What is the difference between carat and karat?
They sound almost identical, they’re both spelled nearly the same, and they both show up in the world of fine jewelry—so it’s no surprise that people mix them up. But while they’re closely related to jewelry, they actually refer to two very different things.
Let’s start with karat, spelled with a K. Karat refers specifically to the purity of gold. Pure gold is naturally very soft, so it’s usually mixed with other metals like copper, silver, or zinc to make it strong enough for everyday wear. Karat tells you how much actual gold is in the metal. For example, 24K gold is pure gold, meaning it’s 100% gold with no other metals mixed in. An 18K piece is 75% gold and 25% other metals. A 14K piece is about 58.5% gold, and 10K is 41.7% gold. The higher the karat number, the richer the gold color and the softer the metal tends to be.
Now let’s talk about carat, spelled with a C. Carat refers to the weight of a gemstone, not its size or its quality. One carat equals 200 milligrams, and it’s the standard unit used to measure diamonds and other gemstones like sapphires, rubies, and emeralds. While a higher carat weight usually means a larger-looking stone, two stones with the same carat weight can look different in size depending on their shape and how they’re cut.
So in simple terms:
✔ Karat (K) = how much gold is in your jewelry
✔ Carat (C) = how much a gemstone weighs
Understanding this difference helps you shop smarter and with more confidence—whether you’re choosing a gold ring, a diamond pendant, or a custom piece made just for you. If you’d like to dive deeper into this topic and see examples in person, be sure to watch the video in this blog where I break it all down visually and answer some of the most common questions I get in the showroom.