How big is a 1 carat diamond?

Wed, Nov 08, 2023

1 carat Diamonds Size Chart

Round Diamond Icon Oval Shape Diamond Icon Cushion Cut Diamond Shape Icon
6.40 x 6.40mm
8.00 x 5.30mm
5.80 x 5.80mm 
Emerald Cut Diamond Shape Icon Teardrop Pear Shaped Diamond Icon Heart Shaped Diamond Icon
6.80 x 4.50mm 
8.50 x 5.30mm
6.00 x 6.70mm
Princess Cut Diamond Shape Icon Marquise Diamond Shape Icon Radiant Cut Diamond Shape Icon
5.50 x 5.50mm
10.50 x 4.80mm
6.60 x 5.10mm


The above list shows the average size for a well cut 1 carat diamond in each of the shapes. But you're probably aware that carat is a measure of weight and not the size of your diamond. So the actual size of a 1 carat diamond, for example, will depend. 

On what? 

Shape and cut.

These are not to be confused with each other! The shape of the diamond being it's geometric appearance and the cut being the exact proportions of the facets and all dimensions, symmetry and angles.


1 carat Single Diamond Necklace
1 carat diamond necklace


1 carat Diamond Bangle Bracelet Gold
1 carat diamond bangle bracelet


Different 1 carat Diamond Sizes

Let's take a round shaped diamond. When cut to ideal proportions, you can expect a diameter of around 6.40mm. However, if we have a deep cut, this can reduce the diameter to as little as 6.00mm or less. This may not sound like much, but side by side, there's a significant visible difference. Shallow cut 1 carat round diamonds can reach up to 6.60mm which may sound good as they'll appear bigger, but the compromise is on the brilliance.


Deep vs Shallow Cut Diamond Illustration


Square shapes such as princess, asscher and square cushions and radiants tend to have a smaller 'face up' surface area. Whereas pears, marquise and ovals are more shallow cut shapes with a larger visible size. We have a chart of carat sizes for all shapes and carat weights if you'd like to dive into the details.


1 carat Diamond Stud Earring Yellow Gold
1 carat diamond stud earrings


1 carat Yellow Gold Engagement Ring
1 carat engagement rings


Now, unless you've seen a lot of diamonds or have a scientifically accurate visual imagination, picturing these millimeter measurements on your or your partner's hand is going to be a challenge. Perhaps the most important questions we should ask are actually:

How does this carat weight look in real life on my hands?


What will this carat weight look like in this ring design?

Photos and videos of each and every design in every carat weight would be useful to an extent, but you'd still be looking at them through a screen. For example in our carat weight guide, we have every shape and every size on a lady's hand.


1 carat diamond on hand


How do 1 carat diamonds look on a hand?

If you'd like to see a ring design on your own hand, with a specific diamond carat weight, you have 3 choices:

Either visit a local store and try on designs there, hoping they have the exact design, carat and price combination that suits you.

Alternatively you can order a ring with the option of returning it for an exchange or refund.

The final option is to order a 3D printed version of your ring before ordering the real thing! This allows you to see the exact proportions in real life and on your hand. For any of our designs, you may contact us to order such a model. To custom design your ring and order a 3D printed model kit, we recently launched Sure Story


 Engagement Ring At Home Try On Kit


November 08, 2023 — Daniel Setton



Daniel is a co-founder of Shiree Odiz, where he focuses on e-commerce, marketing, and diamond selection. With over 17 years of experience, Daniel approaches diamond buying holistically, balancing the technical specs, overall jewelry aesthetic and practical needs of the customer, a perspective that sets him apart from traditional gemologists.