Margot’s Guide to Oval Size Selection

In case you missed it, I reviewed my top 3 reasons for recommending an oval diamond in this post here. 

Now it’s time to chat sizes, and I’m going to let you in on all my secrets!


1. You have been taught for decades to think about a carat size, but did you know it isn’t a size at all? Carat is a weight of a stone, and should not be the deciding factor when selecting. Always look at the millimetre measurement first. It’s possible to have a 1 carat stone that actually measures under 8mm (8mm x 6mm is standard), therefore you want to make sure those mm’s are working in your favour!

My favourite in a 1 carat is 8mm+ x 5mm+, this results in the elongation making your stone look larger.

2. Ratio. Rounded ovals are quite typical in standard cut sizes, and this is when the ratio falls at 1:3 (ratio = length divided by width), so unless you want your oval to look rounded, stick to a 1:4 or 1:5 ratio for your stone.

Two of my favourite oval sizes are: 1.5ct 9x6mm or 3ct 12x8mm 1:5 ratios are the absolute best!

3. Beware of bowties. This is exactly what it sounds like, but looks like a dark bowtie shadow along the horizontal line of your stone. It happens when the cut is compromised, and therefore takes away from the look of the stone. Sometimes when an oval price looks to good to be true, it likely has a bowtie.

4. Use clarity grades to your advantage. It is very rare to see any inclusion in a VS oval, we have also seen success in the Si1 and Si2 ranges. By staying below VVS, you will be able to transfer those savings in to the actual stone size.

5. Work with a diamond expert when choosing your stone. The problem these days, are online databases that often have large selections of stones at sub optimal value. The truth is, diamond prices are very controlled, therefore when something looks like a ‘great deal’ there is usually a reason why. Some of those reasons are: bowties, sub par certifications (not actually reputable), poor cut quality (this is very important for the shine), or unexpected inclusions once your stone turns up.

At Stór by Margot every single stone is selected by Margot, and our team of certified experts. We work all of these categories in your favour, with the goal always being the best possible ring we can make you. Although you may save a bit when choosing your ring online, it usually equals disappointment long term in the overall quality of both diamond and ring design.

We always recommend working personally with a ring designer, to make sure this piece you design to wear EVERY SINGLE DAY, is something that will stand the test of time, and most importantly, that you love it forever.