Carat vs Karat, what is the Difference?

14k yellow gold and diamond bracelets

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Fine jewelry has an enchanting beauty that can often be hard to describe. Luckily, there are technical terms that can be used to express the most important jewelry qualities for easier shopping. Carat and karat are two common terms you’ll likely see when browsing high-quality jewelry. 

Karat and carat both describe different elements of gold and diamonds. Though they can often be used to describe components of the same piece of jewelry, they illustrate completely different things.

Carat describes the weight of a diamond and karat describes the fineness (also known as purity) of gold.

Pieces of gold jewelry will often have both carat and karat values. Learn more about how to understand carat and carat, along with tips for how to pick your best fit. 

The Difference Between Carat and Karat

Six wedding bands including plain metal, gold and diamond styles.

The biggest difference between carat and karat is what they measure. Carat measures the weight of diamonds, while karat measures the fineness of gold. A carat weighs 200 milligrams, while karat measures the purity of a gold alloy in relation to 24 parts of gold. 

Carat Measurements

Three loose diamonds including round, princess and emerald diamonds.

Carat is one of the 4Cs of diamonds, measuring the weight of a diamond. The measurement is often used to weigh other gemstones as well. A carat is 200 milligrams, and this weight can be subdivided into 100 units known as points. This lets jewelers give precise measurements of a diamond’s weight. For example, a 0.50 diamond is one that weighs half a carat or 100 milligrams

It’s most common to find natural and lab grown diamonds listed in the point measurements as this is a more precise way to easily communicate the weight of a gem. 

Carat and Diamond Size

Many people think that a higher carat weight means a diamond will be larger, but this is not always the case. The carat measurement is for the weight of a diamond, not its size. Diamond shapes all showcase carat differently, with some looking larger in the same carat weight. For example, a 1.5 carat emerald cut diamond may look longer and larger than a round brilliant diamond of the same exact carat weight. This is due to the different ways the gems are cut for their shapes. Some diamonds are also cut to highlight specific elements.

Still, there are general expectations for diamond carat and size correlation. Most diamonds of specific shapes and carat weights will have general sizes. You can refer to our diamond size chart to learn more. Always review a specific diamond’s measurements to understand that exact gem’s profile. 

Karat Measurements

Karat is used to indicate the fineness of gold jewelry. Because gold is a softer metal, it is often alloyed with other metals for strength and durability. The amount of gold in a piece is quantified by its karat value, with higher numbers indicating more gold content. 

The purity of a gold ring, necklace, earrings or other jewelry styles will be indicated by a numerical stamp on the jewelry. It’s typically a number such as 14 or 18, followed by a letter K. The higher the number, the more gold in piece. 

Gold jewelry is rated out of 24 parts, with 24k gold jewelry containing 24 of 24 parts gold. This is considered pure gold and is very rare for jewelry. Other popular gold purity levels are 18 of 24 parts, 14 of 24 parts, 10 and 9 as well. 

An 18k gold necklace will be 18 of 24 parts gold, with the remaining 6 parts consisting of other metals such as copper, silver, nickel or zinc. A 14k gold bracelet will have 14 of 24 parts gold, and its remaining 10 parts will be a higher amount of the other metals gold is often alloyed with. 

About 24k Gold

Five pairs of gold and diamond earrings including hoops and studs in yellow and white gold.

Gold is a very malleable metal on its own. To strengthen the jewelry, gold is often combined with other metals to enhance its appearance and durability. Because of this, pure 24k gold jewelry is hard to find. Pure high karat pieces are not as durable as other types of gold that have been alloyed with additional metals. 

Different Gold Karats and Colors

The metal alloying of gold allows for more durable pieces that are perfect for frequent wear. The exact alloy of a single piece of jewelry will influence its color, but there are general guidelines for what to expect from different karat values. With yellow gold jewelry, 18k pieces can have a slightly butterier appearance than 12 or 10k pieces. 

For other colors, the differences in karat values can be less apparent. 14k white gold jewelry will often look indistinguishable from 18k. For rose gold jewelry, 14k styles may be a little rosier than 18k ones. 

Carat or Karat?

14k white gold and diamond necklaces, earrings and bracelet.

Carat and karat are both correct terms when referring to fine jewelry. When discussing diamonds, carat is the correct term. Karat is the correct term when discussing the fineness of gold. 

Questions About the Differences Between Carat and Karat

Carat and karat are both terms used to describe elements of jewelry. Carat is focused on measuring the weight of a diamond or gemstone. Karat is used to describe the purity or fineness of gold. 

No, karat and carat are both different units of measurement for different components of jewelry. Karat measures gold’s purity, while carat measures the weight of diamonds and some gemstones. 

Karat is used when describing the purity of gold, such as 14k, 18k or 24k.

24 karat is used to describe gold and is the most common use. For heavy diamonds weighing 4800 milligrams, 24 carat is an accurate way to describe their weight.

Gold is typically too soft for jewelry on its own, so it is alloyed with additional metals to strengthen it. The karat value of gold is measured in parts of 24. So, 24 karat gold is considered pure gold at 24 parts gold. Other karat values have more alloys mixed in with descending gold purity. 18k gold is 18 of 24 parts gold, 14k has 14 parts gold, 12 has 12 parts and so on. The lowest karat value is typically available at 9k, though 14k is the most popular for style and durability.

Carat is the weight of a diamond, not its exact size. Typically, heavier carat weights equal larger diamonds, though it’s best to check a gem’s exact measurements.

Carat is used when describing the weight of a diamond or gemstone.

Combining Carat and Karat

White gold diamond engagement ring with a round brilliant center diamond.

Both karat and carat are important measurements to consider when shopping for engagement rings, wedding bands, women’s everyday jewelry and men’s jewelry. Each measurement helps to accurately describe the gemstone weights and metal purity of gold styles. 

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