“Karat” vs. “Carat”: What’s The Difference?

When you’re buying gold and diamond jewelry, the difference between karats and carats can get confusing—and expensive—really fast.

That’s because karat and carat are used in similar contexts in similar ways (as units of measure), and in some cases and places they can even overlap.

We’ll break down what each word means, what exactly it measures, and review the different ways they’re used. We’ll even cover the homophones carrot and caret—and why there’s no such thing as 25-karat gold.

Is it karat or carat?

Both spellings are used, but they can refer to different things in different places.

The spelling carat is typically always used for the unit of measure for the weight of gemstones, as in a three-carat diamond.

In the US and some other places, the word karat is used as a unit of measure for the purity of gold, as in 14-karat gold and 24-karat gold. In the UK and other places, the spelling carat is used for both gold and jewels.

What does karat mean in gold?

Pure gold is a very soft metal—it’s so soft it can be bent without even being heated. This makes it extremely inconvenient to make jewelry out of. It’s also very expensive. For these reasons, gold jewelry is often made from gold alloys, meaning gold mixed with some other metal.

The amount of gold in an alloy is measured in karats (or carats, in the UK and some other places). The mix is divided into 24 karats, which are kind of like fractions of the metal.

So, 14-karat gold is made of 14 parts gold out of 24 total parts (in other words, it’s about 58% gold). Gold labeled as 24-karat gold is pure gold, which is why it’s so expensive (and malleable). Karat is commonly abbreviated as k. Common karat values are 10k, 14k, 18k, 22k, and 24k (there is nothing above 24k gold, since it is pure gold).

What does carat mean in gems?

In the context of gemstones, and especially diamonds, carat refers to the weight of the stone. A carat is equivalent to .20 grams. In some systems, the weight of a diamond is divided into 100 points, with 100 points equaling one carat. Diamonds over 1 carat are typically described in terms of their carat value: a 2-carat diamond, a 3.5-carat diamond, and so on.

Obviously, the heavier the diamond, the bigger it’s likely to be, so this measurement is often used, on a practical level, as a measure of how large the diamond is. The biggest diamond ever dug up was the 3,106-carat Cullinan Diamond. But the average size of a diamond in an engagement ring is around 1 carat or less.

Learn about the gems that make every month sparkle as their birthstones.

Carat vs. carrot (vs. caret)

Here’s a golden nugget of etymology, a real gem: the word karat is a variant of the word carat, which comes from the Medieval Latin carratus, a term once used by alchemists. It comes from Arabic qīrāṭ, meaning “weight of 4 grains,” from the Greek kerátion, meaning “carob bean,” “weight of 3.333 grains,” or, literally, “little horn.”

That little horn might bring to mind the somewhat hornlike appearance of a carrot, and in fact carrot has a distant etymological connection with carat. Carrot is rooted in the Greek kárē, meaning “head.”

Interestingly, the mark known as a caret (‸)—the one used to show where something should be inserted—kind of looks like a carrot, but its name is not etymologically related to carrot or carat. It comes from the Latin meaning “(there) is missing,” from the verb carēre, meaning “to be without.”

Examples of karat and carat used in a sentence

Here are some examples that show how karat and carat are commonly used.

• My parents bought me 24-karat gold earrings for my birthday!
• At 18 karats, this bracelet is a less expensive option.
• They keep a 10-carat diamond in the vault.
• The ring will be set with a jewel of three carats.