Diamond Articles

Diamond Carat Weight Explained

July 26, 2017 - Diamond Articles

Whether you are looking to buy diamonds or sell diamonds, understanding carat weight is key. Along with color, clarity, and cut, carat weight is one of the 4 C’s that determines diamond quality. Across the industry, the standard unit of measurement for diamonds and gemstones is the carat. The current carat, defined as exactly 0.20 grams, was formally adopted in 1907. The name “carat” stems from the carob seed—in Ancient times, carob seeds were used to weigh jewelry because their mass was believed to stay relatively uniform. Although this is not true, the average weight of a carob seed was found to be approximately 0.20 grams, inspiring the modern carat.

In this article, we will answer the following questions about carat weight:



Precise measurements are of great importance when it comes to weighing diamonds. Even the slightest change in weight can greatly affect the value of a stone. Carat weight is generally measured to the thousandth of a carat and then rounded to the nearest one hundredth. Specialized instruments are often used to ensure precise measurements.

measuring diamond carat weight



For a general sense of the carat weight of your diamond, you can use WP Diamond’s “Diamond Weight Calculator”. Using the shape, length, width, and height of your stone, the calculator will provide an approximation of carat weight. If you are looking for a precise measurement, the diamond needs to be weighed on a diamond scale.  However, this requires the diamond to be removed form its setting (i.e. your ring).

Once you have this information about your stone, our in-house diamond experts are ready to provide you with a free price valuation. Fill out the online form and one of our team members will be in touch shortly with an initial price quote.  Alternatively, we can advise you of the weight once we receive your item.



The quick answer to this question is that no, carat weight does not directly correlate to size. Two stones of the same weight can have very different diameters and depths and, thus, appear to be very different sizes when set in a ring.



Carat weight has a significant effect on a diamond’s worth. As the size of a stone increases, its price-per-carat grows increasingly higher (all other things being equal). As larger diamonds are rarer, their price-per-carat is generally much higher than a more common smaller stone. Additionally, a diamond that weighs 2 carats is worth much more than a diamond weighing 1.99 carats, a diamond weighing 1 carat is worth much more than a diamond weighing .99 carats, etc. Customers are often interested in purchasing diamonds that they can claim are 2 carats or 1 carat as opposed to a weight slightly lower.

It is also important to remember that two diamonds of the same carat weight can have vastly different values. Carat weight does not tell the whole story of a diamond—a diamond’s worth is also greatly determined by color, cut, and clarity.

To get a price quote for your diamond, click the button below to receive your price quote. We buy your diamonds or diamond jewelry directly, meaning that our secure service can take as little as 24 hours from start to finish. With an A+ Better Business Bureau rating and hundreds of customer reviews, we are a leading, trusted diamond buyer. We pride ourselves on offering unparalleled and expert customer service, transparent pricing and a luxury selling experience. Contact our GIA trained gemologists today for a price quote or with any questions you may have.

Bio: Written by one of our diamond, designer jewelry or luxury watch experts. With over 150 years of combined experience, our experts are able to comment on trends, share industry knowledge and provide diamond, designer jewelry and luxury watch education.

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