Diamond Carat

Ever wonder what that whole "carat" thing means when it comes to diamonds? Learn everything you need to know about diamond carats and size to find your new favorite gem.


Understanding Diamond Carat

Carat is a measurement unit of the weight of both diamonds and other gemstones. One carat is equal to 0.2 gram which is about the weight of a paperclip. Carat weight is not related to how nicely a diamond sparkles. In fact, two diamonds of equal weight can have very different values and brightness depending on the other members of the 4C’s. In fine jewelry, including those at Eternate, diamonds typically weigh two carats or less, but their value depends on achieving that sparkle through other qualities such as cut, color and clarity.

Why is Carat Important?

Among the 4C’s, carat is the one that has the biggest impact on the price. It’s a universally recognized measurement system that assesses the diamond’s value and determines its price and appearance. The higher the carat weight, the bigger the diamond. And bigger diamonds tend to be more noticeable and flashier, which is why they are more desirable and expensive. However, it's just one piece of the puzzle when it comes to picking out the perfect diamond. The balance of the 4Cs is the best way to make a smart and informed purchase.

Carat and Size

Carat might sound like it tells you how big a diamond is, but it is actually about a diamond’s weight, not its physical size. However, a bigger diamond will usually weigh more carats. But a bigger diamond does not always mean a better diamond. Two diamonds with the same carat weight can look very different because of variations in density and cut. That’s why it's important to consider both carat weight and cut when choosing a diamond, so you don't end up paying extra for weight that won't even be visible.


Our carat chart provides a helpful visualization of how various diamond carat weights appear at their actual size, viewed from above, in different shapes. Keep in mind that other factors, like the diamond's proportions (length-to-width ratio) and its cutting style (table size and depth), can also influence its final look. So, your diamond might show some slight variations compared to the chart.


Carat and Size

Why is Carat Important?

Among the 4C’s, carat is the one that has the biggest impact on the price. It’s a universally recognized measurement system that assesses the diamond’s value and determines its price and appearance. The higher the carat weight, the bigger the diamond. And bigger diamonds tend to be more noticeable and flashier, which is why they are more desirable and expensive. However, it's just one piece of the puzzle when it comes to picking out the perfect diamond. The balance of the 4Cs is the best way to make a smart and informed purchase.

Other Factors Affecting the Size Appearance

Carat weight isn't the only factor determining a diamond's perceived size. There are two other factors interfering: cut and shape.

Cut: A poorly cut diamond, even with a high carat weight, might look smaller due to a shallow cut or a thick girdle that hides some of the stone.

Shape: Elongated shapes like marquise, emerald, oval and pear can appear larger than their carat weight suggests because they spread out more. Conversely, round brilliant cuts might show a bit less surface area for their weight due to their more compact form.

How to Make Your Diamond Look Bigger

As carat is not the only factor affecting the size, you can create the illusion of a larger diamond with simple tricks.


  • Band Choice: A thinner, delicate band will put the center diamond in the spotlight.
  • Cut: A well-cut diamond is a sparkly diamond, and a sparkly diamond looks bigger. Go for a diamond with a cut graded "excellent" to maximize light reflection.
  • Halo: Halo is a setting with a circle of smaller diamonds surrounding your center stone. These smaller stones frame the center diamond and add to the overall surface area. The result is more light and brilliance reflected from multiple diamonds at the same time, which gives it a more expansive and dazzling appearance.
  • Shape: Certain diamond shapes like marquise, pear, oval or emerald elongate your finger and make the diamond seem bigger due to their stretched look.


How to Make Your Diamond Look Bigger

Choosing Your Diamond

Consider your budget. Larger carat weights typically cost more. Determine your budget first and then look for diamonds within that range.

Don't just focus on carat weight. While carat weight is important, it's not the only factor that affects a diamond's beauty. The cut, clarity and color also play a significant role.

Look for a good cut. A well-cut diamond will sparkle more and appear larger due to better light reflection. We recommend a cut graded "excellent" or "very good".

Consider near-carat weights. Instead of a 2.00 carat diamond, look for stones around 1.85 to 1.95 carats. The difference in size is invisible to the naked eye, but the price can be noticeably lower.

Think about the setting as it can also affect how big a diamond appears. A thinner, delicate band will make the diamond the star of the show, while a thicker band can make it look smaller.

Consider Lab Diamonds. Lab diamonds are created under controlled conditions and have the same optical and physical properties as mined diamonds. At Eternate, our lab diamonds are all excellent cut to maximize brilliance, which makes them appear larger and also at a fraction of the price. They offer you the chance to own a much larger diamond at a surprisingly lower price than a mined diamond. For more information, check out our Lab-Grown Vs. Natural Diamonds guide.

Don’t forget that there's a whole world of stunning gemstones to explore. Many of them are in fact more affordable than diamonds, but they still allow you to get a durable and high-quality stone. Moissanite, for instance, offers a stunning option with a fiery brilliance that rivals diamonds. Visit our Moissanite vs. Diamond guide for more information.

Jewelry Engraving FAQs:

How big is a one carat diamond?

A one carat diamond will typically be around 6.5 millimeters in diameter. And the perceived size can vary depending on the cut.

What is the highest carat diamond?

The Cullinan Diamond holds the record for the largest gem-quality diamond ever found and it weighs 3106 carats. It was later cut into several polished stones, with the largest one weighing 530 carats.

Which is bigger, 1/3 or 1/4 carat diamond?

A 1/3 carat diamond is bigger than a 1/4 carat diamond.

How to measure diamond carat?

There are two main methods jewelers use to measure a diamond's carat weight. The first and most precise one is with a specialized diamond scale. These incredibly precise scales are calibrated to measure in carats and points (hundredths of a carat). For already cut diamonds, jewelers can sometimes estimate the carat weight based on the diamond's diameter using a formula. However, this method is less precise.

How much does a 2-carat diamond cost?

The price of a 2-carat diamond can vary significantly depending on its quality. But generally, a 2-carat diamond might range from $10,000 to $30,000.

How much is a 4-carat diamond?

A 4-carat diamond can cost anywhere between $40,000 and $100,000 or even more depending on its quality, 4C’s and origin.