Length-to-Width Ratios: A Buyer’s Guide
As if buying a diamond wasn’t complicated enough, an added element that goes beyond the basic 4C’s requires additional consideration: diamond ratios. Luckily, this uncharted territory isn’t as difficult to understand as one might think! In an effort to ease your diamond buying experience, we’ve simplified what you need to know about measurement ratios to help get you to the finish line of finding your perfect diamond!
What is a ‘Length-to-width’ ratio?
Most simply, the length-to-width ratio of a particular diamond is calculated by taking the two first dimensions found on any GIA certificate, the length and the width, and dividing the two numbers. The yield you get from that calculation is the diamond’s length-to-width ratio.
These ratios are most commonly discussed when looking at fancy shaped diamonds (as opposed to round diamonds). The ratio tells you the degree of elongation of any given stone with the constant ratio being 1.00, signifying a perfectly symmetrical and non-elongated stone. The further away any given stone’s length side deviates from 1.00, the more elongated the diamond will appear. There is no set range of ‘ideal’ elongation, or lack thereof, as it is completely dependent on the shape and what is visually appealing.
Everything You Need to Know
When taking the next step in your diamond-buying journey, it is important to gauge how the carat weight and diamond dimensions are key to understanding this concept. The carat weight is only the weight of the diamond; It gives you some indication of size, but the dimensions of the diamond ultimately dictate how much of that weight is visible. For example, a person can weigh 150 pounds and either be 4 feet tall or 7 feet tall. The person’s weight doesn’t change, but the variance in height changes the person’s weight distribution and overall appearance. This same principle applies to diamonds!
There is no ‘right or wrong’ diamond ratio; it all boils down to your personal preference. Once you narrow down your favorite diamond shape, it is easier to grasp what exactly that preference means. Some people prefer extremely elongated stones, as it gives the illusion of the diamond appearing larger, while some prefer a more robust and less elongated stone because it occupies more width on the finger.
There is, however, a caveat to this! Within each diamond shape, there is an “ideal” range based on the cut of the stone. If you deviate too far from this range, aside from increasing the rarity of the stone, this deviation could negatively impact the cut or brilliance of the diamond. Do your homework and make sure you aren’t stretching the dimensions too far in either direction (relative to the shape) as it will impact the sparkle factor of the diamond! This negative impact would be reflected in the price, and would price out much lower than the same diamond falling within that ideal range. As a general rule of thumb, if it’s too good to be true, it most likely is! Luckily we are here to assist you, so you don’t have to worry about any of those grey areas!
Ratios by Shape Guide
CUSHION
The traditional cushion cut is more squared off and symmetrical rather than elongated. If you prefer a more square looking cushion, the closer to 1.00 the diamond is the better; Generally speaking, anything that falls between 1.00 and 1.09 is classified as a more ‘squared off’ and non-elongated cushion. We recommend staying between 1.00 and 1.05, however, to maintain that classic cushion appearance.
The elongated cushion has gained recent popularity in the last few decades, and is classified as any cushion exceeding a 1.10 ratio. The desired range, especially if you like a more rectangular looking cushion, is staying between a 1.10 and 1.30 ratio.
OVAL
The oval shape is famously preferred in more elongated ratios, but again, depending on your preference the standard range falls between 1.30 and 1.60. As shown by the diagram, a 1.30 ratio oval is more plump and may be more suitable for a single stone ring. The 1.60 ratio oval is more dramatically slender and a popular option for those who want to add side stones.
RADIANT
Similar to that of a cushion, a radiant cut diamond comes in two varieties: elongated and square. Unlike the cushion, elongated radiants are the better-known option for this cut. If you like the traditional and more rectangular shape, staying between a 1.15 and 1.35 ratio is prefered to achieve maximum finger coverage. If you are someone that likes the more square option, staying between a ratio of 1.00 and 1.05 will give you the look you want to achieve!
EMERALD
Since these are considered a step cut, emerald cut diamonds are most commonly cut to a 1.45 ratio to maintain the sleek and crisp facets notorious to the shape. Though a ratio in the neighborhood of 1.45 is most common, anything from falling between 1.30 to 1.60 is considered acceptable.
PEAR
The only traditional diamond shape to be asymmetrical, the length-to-width ratio of the pear can drastically alter the appearance of this shape. Staying within a range of 1.40 to 1.60 will ensure maximum sparkle while maintaining the visual aesthetics of a pear shape. Those who prefer a more bottom heavy pear are best opting for a diamond falling closer to a 1.40 ratio, while those who want a more slender point are better suited for a ratio between 1.50 and 1.60.
MARQUISE
The most naturally elongated by nature, the marquise can display an incredible spread based on the ratio of this diamond shape. For this shape, staying between 1.75 and 2.15 is considered ideal. Staying closer to a 1.75 ratio will achieve a softer and more plump looking stone. If your preference for a more sharp and angular look, something closer to the 2.15 ratio is the way to go.
PRINCESS
A classically symmetrical shape, the princess is a shape where most would prefer the ratio to fall between 1.00 and 1.05. Anything between this ratio will appear square to the naked eye. Anything that falls outside of the 1.05 ratio will begin to look more rectangular, though, again this is all about preference. If you have your heart set on a three-stone ring, something slightly out of the range specified above, like a 1.08 ratio, won’t be as apparent with the addition of side stones. This would help supplement the appearance of added width, and it would drop the price.
ASSCHER
The cousin to the emerald, the asscher is a squared step cut with slightly larger facets than that found in an emerald. As it is cut to be symmetrical and square, it is no surprise that most people prefer the stone to fall between a 1.00 and 1.05 ratio. Again, visually, this gives a square appearance to the diamond. The more distant the ratio falls from 1.00, the more rectangular the shape will appear. Stones falling closer to the 1.08 ratio will have a different facet pattern and light reflection compared to the more symmetrical stones.
HEART
The only diamond shape to fall UNDER the 1.00 ratio, the heart shaped diamond is a non-traditional stone that symbolizes the very essence of an engagement. The ratio of a heart is able to dip below the standard 1.00 length-to-width ratio because of the asymmetry of the shape. A wider heart will be closer to a .95 ratio, while hearts falling in the neighborhood of 1.05 will give off a more narrow appearance. The 1.00 length-to-width ratio is still the most ideal ratio for this particular shape.
THE VERDICT
It goes without saying: diamonds are complex gems with a variety of nuances that affect the visual appearance of any given shape. Though these measurements can be quantified in terms of length-to-width ratios, what matters most is what you prefer. Whether a more symmetrical stone looks better with your dream three-stone setting, or an elongated stone is more flattering to your finger, those are judgments only you can make. At Lauren B, we are here to guide you through these decisions and to help you choose a stone best suited for you!
