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Diamond Size Chart: Don’t Get Duped by Carat Weight

When it comes to the beauty at any size movement, we’d like to propose that this idea extends to the world of diamonds. Because, darling, does size really matter? After all, it’s what you do with it that counts. And while carat weight is most assuredly how the industry will continue to price diamonds (tradition, right?), it doesn’t have to be how we judge their beauty or meaning. And just like people, there’s a diamond out there for everyone. What’s more helpful when considering a diamond engagement ring? A diamond size chart! It’s like a super friendly, easy-to-understand guide to what your diamond will actually look like—meaning you won’t get duped into paying more for carat weight that you can’t even see! 

Let’s Talk About Size, Baby

The most important thing to remember about this oh-so-obvious C is that carat weight is exactly that: a measure of weight, not size. Just like you can have two different people, or dogs, or hamburgers that weigh the same but look totally different because their weight is differently distributed. One diamond might be deeper or wider or shallower or longer…than another of the exact same carat weight. So while carat is certainly an important C, it’s actually the least important one when it comes to determining the overall beauty of a diamond.

frank darling 6 carat diamond studs diamond size chart comparison
Did you know that round brilliant diamonds tend to have the most uniform cut and size for their carat weight? Fancy shapes are less consistent!
Cushions can be tricky when it comes to carat weight v. size, so you really want to pay attention to the table measurements!

Fresh Cut

Diamond cut grade, on the other hand, is the most important of the 4Cs to consider when shopping for your stone. Why? Because it 100% determines the overall beauty of a diamond. Okay, okay, so maybe that’s a bit of exaggeration. But really tho—diamond cut has the most visible impact on the sparkle of a diamond, which is what most of us are really after. And in fact, a well-cut diamond can even make up for other shortcomings like lower color and clarity grades…or even a smaller size! That’s right, darlings, you can buy a slightly smaller diamond with a higher cut grade and just the sheer amount of brilliance bouncing back to your eye will make that diamond seem like it’s the same size or larger! Cha-ching!

Apples to Apples

Now, if you’re looking at diamonds that don’t have cut grades (which is any shape other than round!) or you’re just trying to evaluate what you’re paying for when it comes to size, then diamond proportions will come in super handy. Diamond depth and table percentages are typically a good starting point, and every shape (even though there can be a lot of variation) will have its own sort of “ideal” parameters that will give you the most bang for your buck. You also want to make sure that your diamond isn’t hiding too much of its weight with an extremely thick girdle (the widest, center part of your diamond). This means the weight is “hidden” and not accounted for in what you see from the face-up view.

People like to say that ovals “look the biggest for their carat weight” due to their elongation, but this isn’t necessarily true as poorly cut ovals tend to be bottom-heavy!
Frank Darling loose 2 carat emerald cut diamond
Emerald cuts are another shape that often appear smaller than their carat weight would have you believe, due to the depth required to create those mesmerizing step facets.


Yep, that face-up view is kind of a big deal. Because that’s really what you (and everyone else) will see. So whether it’s the diameter of a round or the length-to-width ratio of any elongated shape, use these measurements to determine the real “size” of any diamond. For instance, you can find two same-carat-weight Asscher cut diamonds (or any shape, really) that have different length-to-width ratios because they are cut with different depths and overall proportions. Every facet counts when it comes to diamond size and sparkle. So compare carefully. And if all else is the same, you probably want to go with the slightly larger one, right? 

Just Your Shape

Shape also becomes super important when we talk about diamond size, because some are just naturally shallower or deeper than others, which means they will naturally have different face-up appearances. Ovals and marquises, for instance, are cut quite shallow and their elongated shapes mean that they have tons of spread (the space a diamond takes up, basically) and will look larger than their weight. On the other hand, Asschers and princess cuts are typically cut quite deep, meaning they’ll have a slightly smaller spread compared to other shapes and look smaller for their weight. No matter what shape you choose, just make sure the measurements are within the bounds of ideal proportions and you’ll be golden.

Frank Darling custom 7 carat oval diamond solitaire engagement ring
This oval has a large face and thin girdle, maximizing its face for carat weight!
custom frank darling engagement rings on a hand
All three of these diamonds have the same carat weight, but as you can see the face size varies greatly.

Give ‘em the Finger

Now, not to get too personal, but diamond size (really, the appearance of size) can also be affected by finger size. A one carat diamond will look quite large on a size 4 finger but smaller on a size 10 finger. It’s good to keep your finger size in mind while shopping and find something that looks like a nice proportion for the ring setting of your choice. If you’re not sure what will look good, try ordering a ring flight! Like wine, but sparklier! That’s right, we’ll send you some sample cubic zirconias of various sizes or shapes so you can see for yourself what they’ll look like.

End Game

When it comes right down to diamond size and carat weight, you really can’t go wrong. But if you’re on a budget, spend more on a well cut diamond and a little less on size and you’ll usually be much happier with the end result. Check out our collection to shop more than 10,000 natural and lab grown diamonds or send us a note at with some general info on what you’re looking for and our team of diamond experts will help get your dream ring off the ground.

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