When most people think about diamonds, carat is one of the first words that comes to mind. It’s often thought that carat refers to the size of the diamond, and that more carats simply mean a bigger, better stone. But that’s actually not quite the whole story. In truth, carat refers to weight, not size, and while it plays a big role in a diamond’s value and visual presence, it’s only one piece of a much larger puzzle that is a diamond’s beauty.
Understanding what carat really means—and how it interacts with other factors like cut, shape, and total carat weight—can help you make a smarter, more satisfying choice. At Paul’s Jewelers, we believe the most beautiful diamonds are the ones chosen with clarity and confidence, and we’re here to help you get there.
What Is Diamond Carat?
The carat is a measurement of a diamond’s weight, not its size. One carat weighs 200 milligrams, or 0.2 grams.
This unit of measurement actually gets its name from ancient times, when carob seeds, which hold a mostly uniform weight, were used to measure precious stones. Today, while the tools have become more precise, the term has endured.
It’s important to remember that carat does not equal size. Two diamonds with the same carat weight can look different depending on their cut and shape.
For example, a well-cut 1-carat diamond may appear larger than a poorly cut one due to poor allocation of the diamond along its dimensions.
Total Carat Weight (TCW): What It Really Means
In addition to individual diamond carat weight, you will undoubtedly come across the term Total Carat Weight (TCW) on your jewelry journey. TCW refers to the combined weight of all diamonds in a piece of jewelry—not just the center stone. For example, a ring with a 0.75-carat center diamond and two 0.25-carat side stones has a total carat weight of 1.25 carats.
Understanding TCW is especially important when evaluating multi-stone pieces - for example, halo engagement rings, tennis bracelets, or earrings. While TCW offers a fuller picture of the piece’s diamond content, it’s always worth asking how that weight is distributed—since a single larger stone often carries more value (and visual impact) than multiple smaller ones totaling the same weight.
The Visual Impact of Carat: Cut and Shape Matter
A common misconception is that a higher carat always means a bigger-looking diamond. In truth, the cut and shape of a diamond play a major role in how large it appears.
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Cut Quality: A well-cut diamond reflects more light, making it look brighter and often larger than its poorly cut counterpart. Poorly cut diamonds can inefficiently allocate carat weight across the diamond, leading to a smaller perceived size. For instance, having more of the diamonds weight distributed in its pavilion (depth), leading to a smaller looking stone.
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Shape Considerations: Some diamond shapes naturally maximize face-up surface area. Oval, pear, and marquise shapes, for instance, often appear larger than round diamonds of the same carat weight. Shapes like emerald or cushion cuts may carry more weight in depth, leading to a smaller face-up look.
By considering how cut and shape affect visual proportions, buyers can often find diamonds that look bigger than their weight might suggest, without the premium price tag.
Carat and Price
Diamond prices aren’t linearly proportionate to carat weights. There are two factors to this: the rarity of the raw material needed to create larger stones, and benchmark carats.
Large, gem-quality rough diamonds are much, much less common than smaller ones, which means that as you move up the carat scale, each incremental jump in weight comes with a disproportionately higher cost. Put simply, as the carat weight increases, so does the rarity of the rough stone required to make it.
Furthermore, the pricing of diamonds also jumps significantly along benchmark carats - that is, the round carat numbers that typically demand more attention, and therefore price, like 0.50ct, 1.00ct, 1.50ct, 2.00ct, and so on.
With this in mind, savvy buyers can actually find excellent value by shopping just under a benchmark carat weight.
A diamond weighing 0.90ct or 0.95ct can appear virtually identical in size to a full 1.00ct stone—especially when cut exceptionally well—but can cost noticeably less.
In fact, a well-cut sub-benchmark diamond can often look better than a heavier, poorly cut one. This is a great example of how knowledge and flexibility can lead to smarter decisions and more beauty for your budget.
Carat Weight vs. the Other Cs
While carat is a major factor in both appearance and price, it should never be considered in isolation. Cut, color, and clarity are just as important—if not more so—in determining a diamond’s beauty.
In particular, the diamond’s cut grade plays a heavy role in determining its ability to sparkle and shine.
A large diamond with poor cut and large inclusions would definitely look dull and lifeless compared to a slightly smaller diamond with an excellent cut.
That being said, it’s better to make a compromise and give up a small amount of carat weight for higher cut quality than the other way around.
At Paul’s Jewelers, we understand how tedious it can be to choose the right stone. With a team of experienced jewelers and gemologists on site, we stand by to offer personalized guidance so you can explore your options with confidence.
From explaining the details of TCW to helping you compare visual sizes across different shapes and cuts, we’re by your side to make the process clear, supportive, and enjoyable.
Come in and visit our showroom today, and see why we’ve become Milwaukee’s preferred jewelry destination since 1967.