Karat vs. Carat: What’s The Main Difference?

One of the most commonly mixed-up jewelry terms is karat vs. carat. We’ve lost count of how many times customers have asked, “Wait… aren’t those the same thing?” At Miro Jewelers, we totally understand the confusion. They sound identical, they’re both used in jewelry, and they often appear on the same piece.

But here’s the truth: they mean two completely different things.

Let’s keep it simple. We’ll break down what each term means, why it matters, and how knowing the difference can help you choose jewelry that feels just right—whether you’re shopping for a diamond ring or a gold bracelet.

Here’s the easiest way to remember it:

• Carat (C) measures the weight of gemstones, like diamonds

• Karat (K) measures the purity of gold

That’s it.

If you’re admiring a diamond necklace, you’re talking carats.

If you’re shopping for a gold wedding band, you’re talking karats.

Once you know this, jewelry labels suddenly make a whole lot more sense.

A carat (abbreviated as ct) measures a gemstone’s weight, not its size. One carat equals 0.2 grams.

This is why two diamonds that look about the same size can have very different prices. Carat weight plays a role, but so do cut, clarity, and overall craftsmanship.

In fact, we often show clients diamonds with the same carat weight where one looks noticeably larger. The difference? A better cut. Carat gives you the weight, but cut is what brings out the sparkle.

Understanding carat helps you see value beyond just numbers; it’s about balance, brilliance, and beauty.

Karat refers to the purity of gold. The higher the karat, the purer the gold.

• 24K gold is pure gold

• 18K gold contains 75% gold

• 14K gold contains 58.3% gold

Most engagement rings and everyday jewelry are made with 14K or 18K gold. Why? Because pure 24K gold is soft and can bend or scratch easily.

It really comes down to lifestyle and preference. Do you want something durable for everyday wear, or richer and more pure for special occasions?

Fun fact: both words actually come from the same origin.

Long ago, carob seeds were used to weigh gemstones because of their consistent size and weight. That’s where the word carat came from. Over time, the term karat evolved from the same root but was used specifically to describe gold purity.

Same origin, different meanings.

Gold is always measured in karats—with a “K.”

So if someone says “18-carat gold,” that’s technically incorrect. The correct term is 18-karat gold.

Carat (with a “C”) is only used for gemstones. If you see both terms on one piece, it likely includes diamonds set in gold, such as an engagement ring.

Pretty cool, right? Two measurements working together in one beautiful piece.

The “K” makes it easy to distinguish gold purity from gemstone weight at a glance. It’s also the international standard used in jewelry markings.

So when you see 14K or 18K stamped inside a ring, you know exactly what it’s telling you.

Most fine jewelry includes a hallmark stamp inside the band or near the clasp. Common markings include 10K, 14K, 18K, or 22K.

If you’re ever unsure, bring it to us at Miro Jewelers. We can test your jewelry using professional equipment to confirm its exact karat. It’s a quick, reliable way to make sure your piece is exactly what it claims to be.

It really depends on how you plan to wear it.

• 14K gold is durable and perfect for everyday wear

• 18K gold has a richer color and works beautifully for special pieces

• 24K gold is luxurious but softer and better for occasional wear

For most people, 14K or 18K offers the best balance of strength and beauty.

There’s no single “right” answer. Some people love a subtle 0.5-carat diamond, while others want a bold 2-carat statement piece.

Instead of focusing only on carat weight, think about the full picture—the 4Cs: cut, clarity, color, and carat. A smaller diamond with an excellent cut can sparkle far more than a heavier stone with poor proportions.

Our experts at Miro Jewelers are always happy to help you find the perfect balance between sparkle, size, and budget.

One gram equals five carats. This conversion mainly applies to gemstones, not gold.

For example, a 2.5-carat sapphire weighs half a gram.

A well-cut 1-carat diamond is typically about 6.5mm in diameter. While it may not sound huge, it can look stunning when cut properly.

In fact, we’ve seen 0.9-carat diamonds outshine larger stones simply because they were cut beautifully. Quality always makes the difference.

Carats measure weight—not how big a diamond looks. Two stones with the same carat weight can appear very different depending on their cut and shape.

That’s why we always encourage clients to view diamonds side by side. Seeing the sparkle in person tells you far more than a number on a tag.

Here’s the takeaway:

• Carat measures gemstone weight

• Karat measures gold purity

Two similar-sounding words. Two very different meanings. Both are essential when buying fine jewelry.

Knowing the difference helps you shop with confidence and appreciate the craftsmanship behind every piece.

Have more questions about karat vs. carat? Give us a call at +1-303-393-8881 or email info@mirojewelers.com. Our expert team at Miro Jewelers is always here to help you find jewelry that truly tells your story.