When it comes to diamonds, size does matter.

We all love our diamond rings. In fact, the bigger they come, the better.

Unfortunately, at times you -or your loved one- find yourselves in a situation where your budget doesn’t quite match the rock size you want.

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This is where having a little extra knowledge about diamond size comes in handy, because cut grades (as well as shapes) make the stone look much bigger than its actual carat size.

Let’s see how & why…

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Diamond Cut <> Diamond Size Correlation

Before we start, it’s important to mention that cut isn’t the same as shape, when you hear “round cut”, it generally means the shape. Cut is how well a diamond’s facets interact with light, and graded in 4 grades as per the GIA.

Back to our main topic here:

Do you know that not all 1 carat diamonds appear the same size? Even if they are the same shape!

Yes, that’s true, the carat defines the weight, but not necessarily the size, this is very clear when we compare a round to a heart diamond for example, but how come 2 rounds diamonds (both are 1 carat) are different in size?

Here comes the most important factor of all 4Cs, the CUT.

When diamonds are cut, it’s an art of making the diamond symmetry as perfect as possible, and in order to achieve this, the proportion of diamond facets need to be symmetric.

When diamond has an ideal cut, its proportions will be perfect, resulting in a great shape like this:

Ideal cut diamond

The arrows show how light will reflect from the diamond, resulting in a great sparkle.

Now look at this diamond, which might appear larger (in size, table, and girdle diameter):

Good cut diamond

But are you happy getting this diamond over the first one? Although it appears larger, we bet you don’t.

Simply because the first diamond, even if it looks smaller, it will be way more beautiful than the second one, as it will be reflecting most of the light going through it, unlike the second one, which might look larger only if you inspect it with a loupe!

Diamond Shape <> Diamond Size Correlation

So now after we understood the importance of having an ideal cut for your diamond to guarantee a great sparkle, let’s review the common shapes and see which reflects light better, and which tends to appear larger/smaller:

1. The Emerald Cut

This cut is popular among royalty, so you’re already off to a good start. It is a rectangular shape that features a wide surface, which makes it elongated and looking large.

It might not be the most sparkling cut, but it will certainly look bigger than its actual size. It is a great pick if you want a ring that will grab people’s attention without necessarily blinding them.

In other words, when people look at the diamond, it appears nice and large, but in terms of reflecting light, the emerald isn’t the best shape on that.

Check Out Some Beautiful Emerald Cut Diamonds

2. The Princess Cut

The princess cut is the second most popular shape for diamonds, and with good reason. It’s a relatively newer design, first created in the 1980’s, and is shaped like a four-sided pyramid.

Because of its shape, the sides of the diamonds are jut out, resulting in about a 15% larger measurement on two sides than when compared to a round cut diamond.

Princess cut provides a very high level of light reflection & brilliance, resulting in great diamond sparkle, keep in mind that the princess cut is part of the brilliant cuts family, which are a bit more expensive because these cuts have better light reflection.

Check Out Some Beautiful Princess Cut Diamonds

3. The Oval Cut

An oval cut elongates the diamond as it forms the two ends of the oval.

The oval cut is also part of the brilliant cut shapes, so a good oval cut diamond will definitely have a great sparkle.

Just like the emerald cut, the increased length is what adds to the surface area of the ring, thus creating a perception that the ring itself is massive.

Check Out Some Beautiful Oval Cut Diamonds

4. The Radiant Cut

This cut makes the cut not really because of its shape, but rather because of the way it plays with light.

As its name suggests, it offers maximum sparkle, and flashes in a way that makes demands attention.

If you want to shine, literally, this is the one for you.

Check Out Some Beautiful Radiant Cut Diamonds

5. The Pear/Teardrop Cut

Like the oval cut, the pear cut looks bigger than it actually may be because of its elongated shape.

The main difference between the two is that the pear cut has slightly shaved sides, causing a more dramatic effect as the diamond tapers down.

A lot consider the pear cut as second to the heart cut in ways of reflecting love, as it looks similar to heart shape diamonds.

When people look at your ring, they’ll see the wider surface area on top, without noticing that it slants inward towards your setting.

Check Out Some Beautiful Pear Shaped Diamonds

6. The Round Cut

It all comes down to math and how surface size is calculated, but this timeless style is the clear winner when it comes to making your diamond look bigger than it actually is.

Just keep in mind, since a round diamond doesn’t slant or curve one way or another, it will usually come with a slightly higher price tag than other cuts for the same size.

Because of its ability to reflect light like no other cut, you will notice that out of the popular 10-11 shapes, the round brilliant cut takes the lion’s share with up to 80% of inventory on most stores.

Check Out Some Beautiful Round Cut Diamonds

7. Cushion Cut

Cushion-cut diamonds have earned its name from its pillow shape, it has rounded corners and larger facets to increase their brilliance. Shapes vary from square to rectangular.

8. Radiant Cut

The radiant diamond cut is another variant of the square cut diamonds. It has trimmed corners that combine the lines of an emerald cut with the brilliance of a round diamond. Its modified square shape looks beautifully set with both rounded and square cornered diamonds.

9. Marquise Cut

The marquise cut is a football-shaped diamond. The elongated shape of a marquise cut diamond creates an illusion of a larger looking diamond. It also creates the effect of longer and slender fingers.

10. Asscher Cut

This diamond cut is named after the Asscher brothers of Holland who first produced them in 1902. Similar to the emerald cut, it has a pavilion that is cut with rectangular facets.

Although this is often mistaken with emerald cut, it is square-shaped rather than rectangular with larger step facets.

11. Heart Cut

The heart is regarded by many as the ultimate symbol of love. These stones are best presented alone in single-diamond settings like pendants and rings to match a traditionally romantic couple.

Additional Cheat Sheet

The shape is not the only thing you can manipulate to make your diamond look bigger. Once you’ve selected your ideal style, or decided to work with a jeweler to create a bespoke ring, try combining it with the following design features for even more sparkle:

Choose a white band: a white band will reflect more light compared to any other color band. Again, the reflection will add depth and make the diamond look bigger.

Go for thin prongs: thinner prongs on your ring’s setting means that they will cover less of the diamond. The contrast of the small prongs, compared to the large rock, only adds to its size.

Smaller surrounding stones – if you couple your diamond with substantial smaller stones around it, the center stone will look massive by comparison.

Who says you can’t have the diamond you deserve, or at least make it appear that way until you can upgrade later?

Always make sure to buy from quality sellers. They might even have some further tricks up their sleeves to get you studded out.

We encourage you to browse sites like JamesAllen, Blue Nile, and Whiteflash to have more ideas about shapes & rings, and how each cut looks on actual hands using JamesAllen imaging feature.