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Can You Measure Diamond Weight In Grams? 

Can You Measure Diamond Weight In Grams? 

When shopping for diamonds, a certain amount of people will make the diamond’s size – and, in turn, its weight – their number one priority. There’s nothing wrong with wanting a larger-looking stone. 

Chances are, you’ve heard about diamond carat weight, but can you measure diamond weight in grams?

The answer is yes; you most definitely can – although the most common weight measurement unit used for diamonds is the carat.

In this article, we’ve covered everything you need to know about a diamond’s weight – and its impact on the stone’s value. Read on!

Definition Of Diamond Carat Weight

Before you buy a diamond, it’s essential to understand what carat means. The GIA defines carat as the weight measurement of a gemstone

If you were to ask a diamond seller or jeweler about the weight of a particular gemstone, they’d commonly respond in carats rather than grams.

The carat weight of diamonds is divided into 100 points, where 1 carat equals 100 points. 

So, for example, if a diamond has 0.25 carats, a jeweler will refer to it as a 25-pointer. And for a diamond that has a carat weight above 1, you’ll see decimals and carats. So, a jeweler will refer to a diamond with 1.25 carats as one-point-25 carats.

Related Read: How Can You Tell The Size of A Diamond?

How Much Does A Carat Diamond Weight?

One carat weighs exactly 200 milligrams or 0.2 grams, equivalent to 0.007 ounces. So, a 5-carat stone weighs 1 gram.

Now, since even larger diamonds are relatively lightweight, the carat weight will likely affect the jewelry’s appearance and price for the most part. The physical weight of a diamond ring or any other piece of jewelry will be based on the setting and other components, of course.

Related Read: Diamond Price Per Gram: How Much Is A 1-gram Diamond Worth?

Where Did Carat Weight Come From?

The history of a carat weight as a diamond measurement unit goes back to the earliest gem traders. Before weight scales were introduced, balance scales compared the weights of two items.

Gemstone trades used the carob seed to compare gems and discover their weight. The seeds were relatively uniform in size and weight at around 0.197 grams on average, making them as accurate of a comparison as possible in those ancient times of using balance scales.

The carat measurement we know of today maintains consistency and accuracy due to the caron seed measurement. 

Today, every corner of the world uses carats as a diamond weight measurement unit. So, no matter where you see a diamond, its weight is measured in a recognizable standard.

Difference Between Carat And Karat

When you’re shopping for diamonds and jewelry, you might come across terms carat and karat – but what’s the difference? 

Quick hint: There’s more to it than a difference in spelling.

While “carat” weight is associated with diamonds and other gemstones, “karat” is connected to gold. Karat refers to the purity of gold alloys in jewelry pieces out of 24 parts.

So, 24-karat gold is the purest form of gold you can get, while 18-karat gold is around 75% pure gold and 25% other alloys.

For instance, you could find a gold jewelry piece with 18-karat gold and 1-carat diamond, so be sure not to confuse these two terms.

Related Read: Do Diamonds Weigh More Than Gold?

What Is Total Carat Weight?

If you’re looking for jewelry pieces with mounted diamonds, you might come across the term “total carat weight.” This factor comes with jewelry pieces that feature multiple stones, where total carat weight includes the center stone and diamond accents.

For example, if the diamond in the center of a jewelry piece has a halo of diamonds around it, the total carat weight will factor in the stones in the halo. 

Still, the jewelry information should include the carat weight of the center diamond on its own.

Related Read: What Is A TW Diamond Compared To CW?

How Does Carat Impact A Diamond’s Price?

Generally speaking, diamonds with a higher carat weight will have higher price tags. That’s even more noticeable with big stones; they’ll have an even higher price since they’re harder to come by. 

However, every diamond’s factor contributes to the stone’s price. If the clarity, color, and cut are the same, a higher carat weight means a higher price.

If you were to come by a colorless diamond with a brilliant-cut, nearly perfect clarity but a lower carat weight, the price would reflect these near-perfect qualities. That gem could cost the same or even more than a higher carat weight diamond with yellow color and inclusions.

Additionally, certain carat weights are considered “magic sizes.” You see, at these points, you might see a significantly higher price per carat if everything else is equal. 

GIA explains that the magic sizes associate with popular carat weights. Popularity means more demand – which, in turn, means higher prices. 

These magic sizes occur at the following intervals:

That means that when a diamond passes a magic size, it’ll be more expensive. So, for example, a 1.06-carat diamond will have a much higher price tag than one that weighs 0.98 carats if other factors are the same.

What’s The Price Of An Average 1-Carat Diamond?

Prices of average 1-carat diamonds depend significantly on other factors of the stone. The cut, color, clarity, and shape factor into the average 1-carat stone price. 

A 1-carat diamond would cost anywhere between $2000 and $16000. So, if it has an excellent cut grade, for example, the price will be towards the higher end. 

Of course, if you add the jewelry setting with precious metals to the equation, the prices go even higher.

Related Read: How Much Is A 1 Carat Black Diamond Worth?

Comparing Diamonds Using Per-Carat Cost

If you decide to buy a loose diamond for a ring or any other piece of jewelry, you might find yourself comparing different options. In that case, you would have to compare diamonds by using a per-carat cost

In order to calculate the per-carat cost, you divide the price of the diamond by its carat weight. That will give you the per-carat value – and make it easier to compare stones of different carat weights.

When you compare diamonds on a cost-per-carat basis, you want consistent standards. To get a precise comparison between diamonds, you should compare stones that:

  • Are graded by the same grading entity. Different labs could have varying standards and methods for measuring and grading processes. You can’t compare diamonds if they have entirely different descriptors.
  • Have the same cut and shape. Diamond cuts and shapes require great skill to execute; however, some are more intricate than others. Extra work and time put into the gem’s cut (and shape) will affect the per-carat price. Different cuts make a more brilliant stone, thus making it more valuable. Compare stones with the same cut and shape for an accurate comparison.
  • Have similar clarity and color. Clarity and color are natural aspects of the diamond, making every stone unique. While no two diamonds are completely identical, they can receive the same color and clarity grades. Try to compare diamonds with similar grades for a more precise comparison.

Diamond Carat Weight Vs. Diamond Size

While the carat weight of a diamond and the size of the diamond are relative and connected to some extent, they’re different measurements. 

A diamond size refers to its specific measurements, while carat weight indicates how much the diamond weighs.

Diamond experts use a scale to measure a stone’s weight and an optical measuring tool for the facets’ different measurements, angles, and proportions.

On the GIA diamond grading report, you can see the diamond’s measurements in a separate section. For round brilliant cut diamonds, the numbers represent the maximum and minimum diameters and the depth of the diamond.

If you have any other diamond shape, the measurements are width, length, and depth. 

The diamond carat weight will be listed as such, noting how much the stone weighs.

Of course, a diamond’s carat weight doesn’t always mean that it will have a certain size. That is where the other factors come in, along with various qualities of the jewelry piece the stone is set in. 

As you observe a gem, its size could appear smaller – or bigger – in relevance to its carat weight based on:


The diamond’s cut can give an illusion of a smaller or bigger size. The cut quality grade describes how diamond’s facets catch and reflect light.

If a stone reflects light well, it can appear more prominent. A poorly cut stone may end up hiding more of the diamond once it’s set in a ring or another piece of jewelry.

Diamond’s girdle could be cut too thick, leading to a smaller-looking stone – even with the higher carat weight.


The shape of a diamond has a role in how big it appears. It’s different from the cut since it describes the form the diamond cutter cuts the stone into here.

Elongated shapes such as pear or marquise may appear more prominent than round diamonds of the same carat weight.

Jewelry Setting

The way a diamond is mounted in a ring could impact its perceived size. For example, a halo setting that encircles the centerpiece in tiny diamonds gives the appearance of a bigger gemstone.

A cathedral setting that holds the diamond off the band can also make the stone appear larger. This setting shows off more of the diamond and helps it catch more light, leading to a bigger and more dazzling-looking stone.

Best Carat Weight For Diamond Engagement Ring

In the past few years, the average size of diamonds for engagement rings has been between 1 and 1.5 carats. But that doesn’t mean you should pursue these diamond sizes. 

As you take into consideration what size the diamond for your engagement ring should be, be sure to factor in:

  • Your budget: Since diamond carat weight impacts the price, consider your budget as you make a decision on carat weight. If you’re tight on budget, consider a diamond that falls slightly below the “magic size.” Generally, a 0.99-carat stone would cost less than a 1-carat one and look almost identical.
  • Your partner’s tastes: Some people prefer a larger-looking stone on their ring or other types of jewelry. Other people prefer a diamond to be more subtle. Be sure to talk with your significant other about their preferences and tastes in terms of diamond size to get a better idea of what to get. If you’re shopping for an engagement ring and want it to be a surprise, you can talk with your partner’s friends or family members instead.
  • Your and your partner’s priorities: While you search for a diamond engagement ring, think about which aspect of the diamond’s 4C’s will be a priority. Most people don’t put carat weight as their number one priority, focusing on the gem’s cut, clarity, or color. So, decide whether to get a completely colorless stone, an excellent cut, or one with fewer inclusions.

If your significant other has a particular preference for size but your budget’s tight, you could compromise with the other 4C’s and get a gemstone with fewer and more subtle inclusions or one that’s more yellow than white.

Bottom Line

So, can you measure diamond weight in grams? 

Well, you can because gram is a unit of weight, after all. But the common measurement unit of weight that’s used for diamonds is the carat – and one carat equals 0.2 grams. 

Diamond carat weight is one of the diamond’s 4C’s, meaning it’s one of the crucial factors to consider when purchasing a diamond. 

But while some people prefer larger-looking stones, thus more carats, others prefer more subtle diamonds with lower diamond carat weight.

Ultimately, you should take into consideration all the factors before you make a purchase. 

If you have concerns regarding your diamond’s weight, size – or anything else for that matter – ask a professional jeweler or a diamond expert for help; they’ll provide you with the best advice.