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How Big is a 1 Carat Diamond Ring?

Not all 1 carat diamond rings are the same size. So, we’ve put together a simple diamond size chart to help you understand how different diamond shapes at the same carat weight compare.

Five, four carat diamonds — which
one looks the largest to you?

What is Carat Weight?

Carat, as you might already know, is a measure of weight, not size. Similar to people, each diamond wears it’s weight a little differently. Pear and oval shaped diamonds are wider and more flat, whereas round brilliants and Asscher cuts tend to run deeper. If you’re looking for the most carat for your dollar, look no further then a Marquise. This flat, generous diamond shape not only elongates the finger but looks nearly twice as big as it’s round cousin.

If you’re flexible, switching up the shape can be a great way to get a diamond that looks bigger without costing more, and while historically the round brilliant has reigned supreme, we think the other cuts are just as dazzling. Use our diamond size chart to understand how big a 1 carat diamond ring really is.

The Diamond Size Chart

A visual reference for round, oval, cushion, emerald, pear, Asscher and marquise cut diamonds

A diamond size chart depicting round, emerald, asscher, marquise, cushion, pear and oval diamonds at .5,1,1.5,2 and 3 carats.

Depth AKA Junk in the Trunk

A diamond’s carat weight only tells about 1/3 the story. Here’s the rest

Carat weight on its own can be misleading. That’s because we price diamonds by weight, but talk about them in terms of size.

Two diamonds that are the same weight, but different depths, can face up completely different sizes. Oof. Let’s dig in.

The size a diamond appears is determined by three things: its carat weight, shape, and depth.

We’ve covered carat weight and shape. What’s depth?

There are two ways of measuring depth.

  1. The actual measurement from the top of the bottom to the bottom of the diamond.
  2. The total depth / the average diameter * 100. This gives you the depth percent, and is the number we use when referring to depth. You can generally find it on the diamond’s certificate. Sometimes it’s not listed. Usually, this is because the diamond’s too deep.

Round Brilliants & Depth

If you’re considering a round brilliant you can rest assured that if you’re buying an ideal or excellent cut diamond it’s depth is a non-issue. That’s because round brilliants are the only diamond that receives an official cut grade from the lab that graded it. Curious how diamonds are graded? Learn more here.

Fancy Cuts & Depth

Fancy cuts are a bit more complicated. Fancy cuts, basically anything but a round brilliant, do not receive an official cut grade. But what about all those grades you see online you ask? They’re made up. Each diamond retailer has their own system for evaluating and assigning grades to fancy cut diamonds. Generally, the grade is a combination of the diamonds table, depth, crown angle, symmetry and polish with varying levels of stringency.

If you’re buying a fancy cut online you’ll want to dig into the details to understand how well the diamond is cut. Take these two Asscher’s, both 1 carat. One’s small, the others smaller. Which one would you want? How would you know?

Diamond size chart comparing two 1 carat Asscher diamonds
Diamond size chart comparing two 1 carat Asscher diamonds

“Spread” No. We’re Not Talking about Peanut Butter

You might hear a diamond dealer use the word “spread” when referring to a diamond. A “spready” diamond is one that looks bigger then it is. Spready diamonds give you more bang for your buck because they’re more shallow.

But — because there’s always a but, spread isn’t always a good thing. If a 1 carat diamond ring is too spready it can look dull and lifeless. You want to look for the sweet spot where it’s not too deep and not to shallow. This varies from shape to shape. Generally, these are the ranges we like to see when we look at depth. The lower the number, the greater the spread.

Diamond size chart showing average depth range for round, oval, emerald, asscher, pear and marquise cut diamonds

Diamond Shape – Your New BFF

Choosing a shape isn’t just about the look, it’s also about the size. As we saw above in the diamond size chart above, there is an incredible amount of size variance between the different shapes.

If you’re looking for a 2 carat look on a 1 carat diamond ring budget consider the oval. Sparkly, spread and shallow. In fact ovals are so shallow, that a .7 carat oval diamond can look as large as a 2 carat Asscher diamond as shown below.

You’ll want to be thoughtful about your choice of diamond shape because you may end up with a much larger, or smaller diamond than you were expecting.

Diamond size chart comparing a .7 carat oval to a 2 carat Asscher
Diamond size chart comparing a .7 carat oval to a 2 carat Asscher

How Big is Too Big?

If Paris Hilton has taught us anything, there’s no such thing. Carat weight is a personal preference. Some people prefer a minimal and dainty look, others want that in your face, across the room sparkle. So, is a two carat diamond is too big? What about a three carat? The only person that can answer that, is you!

Ring size chart comparing 2 carat round diamonds on different ring sizes

The Finger Size Conundrum

While our diamond size chart is a great place to start, there’s no substitute for trying on stones in real life. A one carat diamond can dwarf a size three finger, and look tiny on a size nine. Not sure your ring size? Be sure to check out our guide to measuring your finger at home. A shape that’s flattering on a more elongated finger may look less attractive on one that’s shorter and wider. A stone set north-south can read much smaller than one set east-west. So what’s a hopeful diamond engagement ring buyer to do?

When in Doubt — Order a Stone Flight

Check out our free try at home kit to test drive different one carat settings in the comfort of your home. Think wine, but with diamonds!

Read to Get Started?

Check out our diamond search where you can view 360-degree images of more than 10,000 diamonds and don’t forget to zoom out (because size can be deceiving), or book an appointment at our New York salon to view certified lab-grown and natural diamonds in person. 

Not finding what you’re looking for? Email us with what you’re looking for at We’ll curate a list of 5-7 exclusive stones that are just right for you.

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