• Wedding Day Diamonds

Just How Big is a One Carat Diamond?



Ahh, the one-carat diamond. It’s the stone we all hear about, the one we’re supposed to aspire to, right? But just what does a one-carat diamond look like? How big is it really? It turns out the answer isn’t as straightforward as it seems.

It may surprise you to learn that not all one-carat diamonds are the same size. How can that be??? Remember… a carat is a measure of weight (or volume), whereas size is measured in dimensions, such as millimeters. So, while two different stones can both have the exact same carat weight, they can appear vastly different in size. This difference is especially startling when you compare diamonds of differing shapes.

We’ve talked a lot about cut before, and how cut is responsible for up to 60% of the worth of a diamond. What we haven’t talked about as much is what goes into a great cut, and how every shape of diamond really has its own ideal proportions.

What is meant by proportions?

Proportions refer to the ratio of a diamond’s depth, width, and table.


Width is pretty obvious… when you look down at a diamond from above, how wide is it at its widest point? That is its width.

Table is only slightly more complex… when a diamond is mounted in a ring, the uppermost flat surface of the diamond is its table. The table is surrounded by “shoulders” or the diamond’s crown… those are the angles that slope down and away from the table. Together, table plus crown equal everything you can see of your diamond once it’s mounted in a ring. In other words, the table and crown account for how big a diamond looks, not how big the diamond actually is.

And this is because of depth.

Depth is absolutely everything happening beneath the diamond’s widest point. Remember, carat is a measure of weight… and that means a diamond that is cut deep will be carrying more weight, even if it doesn’t look that big. Contrarily, a diamond that is cut shallow might have a really big table, and be really wide for its weight. It might look big, even if it doesn’t weigh much.

But before you rush out and look for the shallowest diamond you can find, remember, cut is responsible for 60% of the worth of a diamond, and that’s because a diamond cut too shallow (or too deep) won’t sparkle as it should. It will look dull and lifeless no matter how you mount it, because its cut will be incapable of properly reflecting light.

But there are completely valid ways to get a dazzling, fiery diamond that also looks big for its size.

Remember how we said every diamond shape has its own ideal proportions?


The truth is, some shapes simply need to be cut deeper to really sparkle. Princess diamonds (pictured, left) are one of these cuts. So are round brilliants (the world’s most popular diamond shape!)

But other cuts, such as ovals, pears, and marquise, could have a wide table, and a relatively-shallower depth. That means once these shapes are mounted, more of the total carat weight remains visible, offering you a diamond that actually looks big for its size.


Let’s compare:

Every diamond pictured weighs one-carat. Just look at how different the dimensions can be!


Another way to make your diamond seem bigger than its weight is to mount it in a halo. The added sparkle will have the illusion of making your center stone seem larger.


Likewise, a solitaire mounting can also help a diamond to look bigger.

Because there are no distractions in a solitaire ring, the eye will always go straight towards the diamond, and that has the effect of making the diamond stand out more, and seem larger. This is especially true when the diamond is mounted over a delicate, narrow band.


The takeaway:

If you are someone who really wants a big diamond, bigger perhaps, then you think your budget will allow, don’t jump immediately to upping your budget, and don’t at any point opt for a poorly cut stone. Instead, take a look at fancy diamond shapes.

They’ll be every bit as beautiful as more traditional, round brilliants, but their wider, shallower proportions mean you’ll continue to see more of your diamond even after it’s mounted. The result will be a stunning ring with a center diamond that really does appear big for its size.

For even more tips on getting a diamond that is both big and breathtaking, check out our articles on Eco 4’s lab-grown diamonds. You’ll be amazed at just how far your money will go, and just how attainable that one-carat diamond actually is.