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Length to Width Ratios: What’s Ideal Elongation?

By Stephanie Dore

More than any of the 4Cs, the shape of your diamond is it’s most noticeable characteristic. Okay, so maybe sparkle is up there, but humor us. Sure, there are round diamonds, and they’re classic for a reason, but there are so many other shapes to choose from! And these so-called fancy shapes can save you serious cash. But no two are alike. When it comes to picking your perfect diamond shape, length to width ratio is key. Do you like a short, squatty stone? Or something more elongated? Let’s talk ideal diamond ratios, darling!

What is Length to Width Ratio, Anyway?

Remember how you wondered when that math class would really come in handy? Just us? Well here’s the real world example. For any shape other than round (which is obviously round and should be measured by diameter across its widest points), figuring out what ratio you like is one of the most important parts of buying a diamond. Because fancy shapes (anything other than round) are measured in length by width. And while length and width alone will tell you the size of the diamond, it’s the length divided by width (the length to width ratio) that will tell you just how relatively square or rectangular a fancy shaped diamond is when viewed from the top. 

A length to width ratio of 1, for example, would be square (where the length and width are the same); while 1.25, 1.3, or 1.5 would be progressively more elongated. Each different diamond shape has ideal diamond ratios, or at least somewhat standardized or popular length to width ratios. But ultimately, what you like is what you like, so knowing what you’re looking for is key.

platinum radiant cut clutch half bezel ring on hand
Want a look that adds instant length to your finger? Narrow your search to elongated shapes!
2ct oval two tone solitaire 4 prong engagement ring
Ah ovals, the trickiest of all the diamond shapes. You’ll want to build a list of deal-breakers when it comes to your perfect oval before diving into your search!

Oval Length to Width

Oval cut diamonds have been quickly creeping up the popularity charts over the last few years, and it shouldn’t come as too much of a surprise. For one thing, due to their elongated shape and shallower depth, they display a lot of visual spread, which means they face up looking at least 10% larger than a comparable weight round diamond for about 25% less cost. We call that the ultimate win win.

But ovals can also be tricky to shop for and their length to width ratios can majorly impact their look. While many folks tend to prefer a more elongated shape, they can be a bit harder to find (because it’s harder to cut elongated stones from diamond rough). You’ll most often find them in the 1.3-1.5 ratio range. Lower means more round, higher means more elongated. One thing to watch out for, however, is that the more elongated the oval, the more obvious its bow tie becomes. One other thing to watch out for is the “moval” which is like an oval and a marquise cut that had a baby. The oval’s ends will be slightly pointed instead of sumptuously curved. It’s not a no-go, just a know before you go.

Emerald Length to Width

The sophisticated, step cut facets of the emerald cut diamond make it a classic choice that will never go out of style. And compared to its square cousin, the Asscher, an emerald is usually more popular due to its elongated shape (because it makes it look bigger, obviously). But what’s the perfect length to width ratio? If you land in the 1.30-1.45 range, that’s gonna be the sweet spot for balance and for what you’ll find available on the market. But if you really love a longer look, you can hunt for a higher, say 1.6, ratio or similar. If you go under 1.3 an emerald cut diamond will start to look more square and kind of like a wonky Asscher instead of a purposefully elongated stone.

Frank darling north south half bezel lab grown diamond engagement ring in platinum
You can’t go wrong with a well-cut, perfectly elongated emerald!
custom jewelry half bezel pear moissanite engagement ring
There are two camps when it comes to pears: long and slim, or short and wide. Which one do you side with?

Pear Shaped Length to Width

The ultimate mixed bag, a pear cut diamond is halfway between a round and a marquise, boasting one round end and point pointed. You’ll also hear them referred to as teardrop shaped diamonds. And they’re kind of having a moment. Just look to celebs like Ariana Grande or Megan Fox for examples of toi et moi pear cut diamond engagement rings. But you do have to be careful, because these fruity beauties can be a bit tricky when it comes to cut.

Because a pear cut has a wider, more rounded bottom, you’ll see higher ratios like 1.4-1.7. A 1.5 length to width ratio is a pretty perfect balance for a pear cut, while anything 1.6 and over will really give you that extra-elongated look if that’s your style. When giving any potential pear diamond a perusal, make sure to study its overall proportions. Because of its mixed cut, a pear might have uneven sides, curves, angles, etc. And no one wants a wobble. 

Marquise Length to Width Ratios

Don’t let this sleeper hit fool you, marquise diamonds are still fully in style. And with today’s east-west setting style inclination, they’re one of our new BFFs. Equally timeless and on trend, marquise diamonds are also like the definition of elongated diamond shapes. They have major spread, will save you a pretty penny, and can be set in countless cool, modern ways, just as long as you protect their points! Marquises are also super versatile. Long or short, a marquise diamond can do it all.

As far as the market goes, you’ll find lots of marquises in the 1.85-2 length to width ratio range. If you want one that’s extra stretchy, reach for a 2.15 and you won’t be disappointed. On the other hand, if you like a shorter, wider look that’s more football-like, a 1.7-ish ratio will do the trick. Similar to ovals, however, keep in mind the bow tie effect when searching for a marquise, as they can get noticeable the longer the diamond.

marquise with pears three stone in yellow gold
The varying elongation of marquise diamonds totally impacts the look, so have an idea of what shape you prefer!
elongated cushion cut diamond engagement ring.
Elongated cushions may be hard to come by, but the right one makes the dreamiest stack.

Cushion Cut Length to Width

Cushion cut diamonds can play two ways. Many folks like them because in their more square form they can almost look like a round diamond but for less cost. This also makes them super versatile when it comes to setting options. A square cushion cut diamond will have lots of curve appeal, but an elongated cushion cut, in our eyes, is even cuter. 

At 1 length to width ratio, your cushion is basically a softened square, which is to say not elongated at all. Hit 1.1 and you start to see the soft rectangle shape. But you can definitely bump that up and at a whopping 1.3 get the higher end of elongation. Now, anything in between is fine, but that 1.15-1.2 range is the super sweet spot of balance. Cushions can be super cool elongated into an almost pill-like form, however, and make for a great east-west set option that’s edgy but with a softer side.

Radiant Cut Ratios

Another stone that can go either square or rectangular on the regular is the radiant cut diamond. A mixed cut that has cut corners (instead of sharp points) and brilliant faceting, radiant diamonds are like the ultimate mashup. The closer you are to 1:1, the more square your stone. Most of the market will fall in the 1.15-1.35 range, but you can go higher, even up to 2:1 for a super elongated look. 

As with any elongated diamond shape, the length to width ratio you like should be considered hand in hand with your fave setting style. For instance, if you’re wanting that on-trend east-west style engagement ring, go for a more elongated stone, to really give you that horizontal spread. More square shapes, however, can look amazing when set in, say, a five-stone ring. If you’re going for a simple solitaire, then just your luck, anything will do!

radiant diamond and pear toi et moi diamond ring
Radiant cuts are quickly rising in popularity, which means they’re availability is more and more limited!

The Right Ratio

Ready to see some diamonds for yourself? Check out our diamond search where you can view 360-degree images of more than 10,000 diamonds and don’t forget to zoom out (because size can be deceiving), or book a virtual or offline appointment at our New York salon to view certified lab-grown and natural diamonds in person. Not finding what you want? Email us with what you’re looking for at We’ll curate a list of 5-7 exclusive stones that are just right for you.

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