Tips and Tricks

Oval Brilliant MM to Ct Guide by Rare Carat | Rare Carat

On the lookout for an oval cut diamond? No surprise there, these stunners are consistently in the top three for most popular diamond cuts. In today’s market with most purchases done online, it’s important to know what you’re buying with as much accuracy as possible without seeing it in front of you. This guide will help you ensure the diamond you order is the size you thought it’d be. We will be talking in millimeters today, so let’s bust out the metric rulers and get started!

Measuring A Oval Cut Diamond

While estimating the size of your future oval brilliant, it’s probably self explanatory, but the length measurement correlates to the stone top to bottom. Meanwhile, the width is measured around the middle of the stone. Or to make things easier the larger measurement is the length and the smaller is width. Not every diamond is the same, so while the chart below helps you measure an ideally cut oval brilliant of varying carat weights, there may be a very slight difference in size. Although, when I say slight I mean 0.2 mm, so It won’t make any difference. oval bow tie nasty .png

The Bow Tie Effect Doesn’t Make You the Belle of the Ball

While looking for your perfect oval brilliant, be on the lookout for the “bowtie effect”. Before you get too excited, no, it’s not as regal as it sounds. Ovals, marquise, and pear cuts are plagued with this phenomenon. Basically, a bow tie is a distracting shadow that can take away from the beauty of the stone if it’s prominent enough. The before mentioned cuts all have this feature to a degree, but you want to ensure the bow tie isn’t distracting your eye from the stone’s overall charm.

A Little Goes a Long Way

One feature that helps oval shaped diamonds stand above the rest is how its’ apparent carat weight is higher than its’ actual carat weight. Basically, because of an oval’s subtly elongated shape, it tricks the eye into thinking the stone is bigger than it actually is. This is a great tidbit to keep in mind if you want the biggest stone you can get (So pretty much everyone).


If you have any questions or want any clarification on this chart, or anything really, you can type your query in the chat bubble on the screen to get in touch with the gemologist Rare Carat has at the ready around the clock. Now that you know what carat you're looking for it's time to start shopping!

Elizabeth Callnan
Elizabeth Callnan
Elizabeth grew up toddling around in her Grandfather's rock shop which shaped her love and passion for gemstones. Started by her Great Grandfather, she has definitely followed in her family's footsteps. She has recently completed her Graduate Gemologist courses at the GIA and is now working on studying pearls. When she's not adoring the dazzle of gemstones (or writing about them) she's enjoying the captivating beauty of her home state, Hawaii!