Jewelry

Carats vs. Karats: What’s the Difference?

Confused about when to use carats vs. karats? Here, we break down the difference between the jewelry terms. 

By 

Meyme Nakash

 |  August 20, 2025

Walk into any jewelry store, and you’ll likely hear the words carats and karats used in various contexts. While these terms may sound the same, they refer to two entirely different aspects of jewelry, which many find confusing at first. At La Patiala, we firmly believe in the importance of understanding jewelry terminology, especially the difference between carats vs. karats, so that one can purchase jewelry with confidence. Below, we define both terms, dive into their etymology, and discuss their practical applications. 

In This Article 

• What Is the Difference Between Carat and Karat?
• Where Does the Term Carat Come From?
• Where Does the Term Karat Come From?
• Carat and Diamond Size
• Understanding the Different Karats

Carats vs. Karats: What’s the Difference?

Whether you’re entranced by a glittering diamond or drawn to the deep glow of rich yellow gold, knowing the difference between carats vs. karats is essential to making informed decisions as a buyer. 

What Is the Difference Between Carat and Karat?

The primary difference between carats vs. karats lies in what they measure. The word carat is a measurement unit of the weight of gemstones, particularly diamonds and other important precious stones. It’s one of the four Cs, along with cut, color, and clarity, which you can read more about in our guide to the diamond grading system. Although carat weight can influence the value of a gemstone, it isn’t the sole factor determining size. Shape and cut are also significant contributors to how small or large a stone appears (which we discuss further below).

As for karat, this term refers to the purity of gold. Pure gold (24 karats) is soft and prone to scratching and bending, so jewelers commonly mix it with other metals to strengthen it (read more here). The karat number helps buyers understand how much actual gold is in a piece of jewelry, which impacts its durability and value. 

Where Does the Term Carat Come From?

The term carat comes from kerátion, meaning “carob seed” in ancient Greek. Carob seeds were a common standard for weighing gemstones in ancient times due to their remarkably uniform weight. Over time, the practice of weighing gemstones became formalized, and a carat came to represent a specific unit of weight. In modern times, one carat is equivalent to 200 milligrams, or 0.2 grams. This universal standard was adopted in the early 20th century to ensure consistency in the trading and appraising of gemstones. Though we no longer use carob seeds as a method for weighing precious stones, the name lives on as a reminder of humanity’s fascination with dazzling diamonds — and the desire to measure their worth and beauty. 

Where Does the Term Karat Come From?

The term karat originates from the same root as carat, the carob seed, but its meaning has evolved over time through its association with gold purity, specifically during the Roman Empire. After Emperor Constantine introduced the solidus, a coin that weighed 4.5 grams and was made of pure gold, it became the standard for comparing the purity of other coins. This gave rise to a system that divided gold purity into 24 parts, in alignment with the weight of the solidus, which weighed 24 carats (not in the modern context of diamonds, but the unit derived from the carob seed). In other words, if an item is pure gold, all 24 parts are gold, meaning there are no impurities or metal alloys. If it’s 18 parts gold and six parts alloys, it’s 18-karat gold, and so on.

The jewelry industry still uses this system today to describe the purity of gold. Many jewelers refer to karat weight by the letter K. So 18 karat and 18K gold mean the same thing. 

Carat and Diamond Size

Many people mistakenly assume that the weight of a diamond or gemstone indicates visual size. However, how small or large a one-carat diamond appears depends on several factors, the first of which is the cut. A well-cut diamond reflects more light, and, therefore, appears larger and more brilliant than a poorly cut stone of the same carat weight. Shape also plays a critical role in the appearance of gemstones; elongated cuts such as pear, oval, and marquise tend to create the illusion of greater size, compared with round or cushion cuts. 

Finally, depth and table proportions have an important bearing on the weight distribution of a diamond. If the gemstone’s weight is hidden in its depth, then it may appear smaller from its top view, which is typically what people see. As such, while carat weight may set the foundation for the visual size of a diamond, the interplay of cut, shape, and proportions is equally as important to a diamond’s visual impact.

Understanding the Different Karats

Knowing how much pure gold is in a piece of jewelry is critical to your purchase, as it affects everything from value and appearance to durability. Higher-karat gold has a richer hue and is more valuable than lower-karat gold, but it’s also softer and unsuitable for everyday wear. By learning more about the different karats, you can find the right balance between style and longevity when purchasing gold jewelry.

14K Gold and Below

Jewelry made from 14K gold and below contains a higher percentage of alloy metals, making it ideal everyday jewelry and suitable for someone who has an active lifestyle. This comes at a cost, of course, because as the gold content drops, so does its rich color, value, and resistance to tarnishing. A common choice for daily-wear fine jewelry is 14K gold, which contains 58.3% pure gold and 41.7% alloy metals, such as copper, silver, and zinc. This blend is more durable and resistant to scratching than higher-carat gold, although it’s slightly duller in color. 

Once a piece’s gold content drops below 14K, containing significantly more alloys and less pure gold, it will tarnish more easily, potentially cause skin irritation, and have an overall dull appearance. For example, 9K gold has just 37.5% pure gold, increasing the risk of these issues, which explains why it’s more affordable than higher-content gold. Therefore, La Patiala doesn’t recommend anything below 14K gold for fine jewelry. It’s common in demi-fine jewelry. 

Read More: Gorgeous Yellow Gold Jewelry for Every Occasion

18K Gold

18K gold contains 75% pure gold and 25% alloy metals, offering a fabulous balance between beauty and durability. Its high gold content gives it a deep, warm color that’s noticeably more vibrant than lower-karat offerings, which is why it’s a favorite for fine jewelry and engagement rings. Though it’s softer than 14K gold, it’s still strong enough for regular wear if you care for your piece properly. This means avoiding harsh chemicals such as chlorine and household cleaners, storing it separately in a lined jewelry box or soft pouch to prevent scratching, and cleaning it gently with warm water, mild soap, and a soft cloth rather than a harsh brush. Most fine and high jewelry from prestigious brands uses 18K gold or platinum. 

22K Gold and Above

Some of the most luxurious and valuable pieces of jewelry use 22K gold and above, containing 91.6% to 99.9% pure gold, due to its deep yellow color and natural luster, which is highly desirable in regions such as India and the Middle East. However, its stunning appearance comes at the price of being softer and more malleable, which can ruin intricate designs and cause pieces to bend or lose shape over time. This is why jewelers use 22K gold in pieces intended for occasional wear or as collector’s items. However, some brands, including Gurhan and Coomi, use 22K gold in their collections, which showcase the rich color of the gold. 

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