Which Diamond Shape Looks the Largest?

One of the first things you learn about diamonds is that they are sold by weight rather than size. Carats count!

Of course, most one-carat round diamonds will be pretty similar in size, although there will be variations depending on proportions. Ideal cut diamonds, which are cut for sparkle rather than size, are slightly smaller in diameter than less-brilliant “spread” diamonds (which are intentionally cut a bit shallower so they can appear wider.)

However, what might surprise you is that fancy shapes have different ideal proportions than rounds. Each shape has a slightly different depth, so the diameter is different too. If you have a swimming pool that’s 10 feet deep, it’s going to be smaller across than a pool that has the same amount of water that’s only 8 feet deep.

That means that some fancy shapes look larger than a round brilliant of the same weight and some look smaller. A two-carat round brilliant is about 8.1mm across. A two-carat Asscher cut is about 7mm square so it doesn’t look quite as large. In contrast, a two-carat oval is about 10.5x7mm. Most people say that it looks much larger than the other two shapes than you’d expect.

Why? The effect of the overall shallower depth of the oval cut is exaggerated by the tendency we all have to assume that taller shapes are larger. This visual trick makes the elongated silhouette of many fancy shapes look even larger than their surface area might suggest.

These two diamonds might look similar in size but the round brilliant is 3.00 carats and the oval diamond is 2.50 carats. That’s a big difference in carat weight and budget!

If you are considering a fancy shape diamond, the apparent size difference might tip the balance. (Because when it comes to diamonds, it’s really hard to argue with looking bigger.)

Intrigued? Here are some side-by-side images we took of fancy shape diamonds and round brilliants that weigh the same so you can see the way the shape affects the apparent size.

Here are six 1.25-carat diamonds in different shapes. See how the elongated shapes look larger? In particular, the marquise, pear-shape and oval on the bottom row face-up with a larger appearance, don’t you think?

Here are five two-carat diamonds in different shapes. Which shape looks the largest to you?

Interested in another shape or size shape or size, this handy diamond carat size chart will help you judge the average size.

We have one more fancy fact that will surprise you. In general, fancy shapes cost less per carat than round brilliant shapes of the same quality too.

So for the same budget, you can afford more carats, which will mean that your fancy diamond will look even larger than the comparisons shown here.

Try an intelligent search for a fancy shape diamond using your budget and you’re sure to find a diamond that catches your fancy.