What is the Average Diamond Size for an Engagement Ring?

Big rocks rule the mainstream diamond world. But experts know it’s the cut that will make or break the bling factor. If you consider the diamond cut first, then you can go as big as you like. Level with celebrities proposing with 3 carats and beyond or opt for something modest.

Average Diamond Size for Engagement Rings

Although it’s the thought that counts, they say you don’t want to go too small as most women prefer a diamond just big enough to appreciate. But what size is that exactly? What is the Average Diamond Size for an Engagement Ring? I asked James Allen, and this is what we came up with:


Country Average Diamond Size Average Cost
United States 0.9 carat $6,000
United Kingdom 0.6 carat $2,600
China 0.5 carat $2,000
Japan 0.3 carat $2,000

0.90 – The Average Diamond Size for an Engagement Ring in 2017

James Allen Carat Size Simulator

Being the top online diamond shop today, James Allen deals with hundreds of transactions on the daily, so it’s safe to assume that their average carat weight is pretty accurate.

Since their market is also the average American consumer, 0.90 is just right. Not too big and expensive, and not too small and unnoticeable.

If you want to see what a diamond with a certain carat size looks like, check out this James Allen's carat size simulator:


It will make you realize that the diameter of a diamond isn’t equivalent to its carat weight, and a 2 carat will not appear twice as large as a 1 carat!

How Will This Magic Number Help Your Search?

Well, knowing more about the different carat sizes and their costs will make you a more adept shopper. Many people are actually very intent on getting a diamond with at least 1 carat.

They want to be able to say that their diamond has 1 carat or more because it supposedly sounds good. However, diamond prices increase sharply at the 1 carat mark and in fact, most diamonds are cut to make it to the in-demand mark.

Average Diamond Size 2

You will find a lot of diamonds with 1 carat or 1.01 carat, but you will hardly find 0.98 or .99 diamonds! That is no coincidence, and most diamond cutters will sacrifice the cut to gain more carat weight.

Let's have a look at a price list taken from James Allen. I have chosen the three cheapest diamonds with at least 0.9 carat, G color, VS1 clarity, and an Excellent Cut grade:

Average Diamond Size 0.90 -1 Average Diamond Size 0.90 -2 Average Diamond Size 0.90 -3

Then I picked the three cheapest 1 carat diamonds with the same specs:

Average Diamond Size 1 Carat -1 Average Diamond Size 1 Carat -2 Average Diamond Size 1 Carat -3

The difference is about $2,000! The additional carat weight from 0.9 to 1.00 is only 11%-12%. However, the price increase from $5,000 to $7,000 is 40%! It is for this reason that you can make the greatest deals with diamonds at around 0.90 carat!

Now, I’m well aware that most people want to buy a diamond with at least one carat because the number appears to be smoother with a 1 instead of a 0 as the first number in carat weight.

If you badly want to buy a diamond in this size, I absolutely think that you should go for it. However, you should also take in mind that a diamond below one carat could be so much cheaper and the difference in size will hardly be visible.

Should You Consider the Average Diamond Size for Your Engagement Ring?

Average Diamond Size for Engagement Rings James Allen

If you want a decent size that will save you money, yes! But to be honest, if you ace your proposal, it won’t matter if it’s a 0.5 carat or a 3 carats. She’s going to say yes to you, not the diamond size.

So, don’t pressure yourself. This is not an obligatory criterion. If you’re really keen on showing off a huge rock, find the best cut possible then choose the carat weight to your liking.

The average diamond size is only a guideline – a magic mark that depicts society standards but can also get you the biggest bang for your buck once used wisely!

 Smart Diamond Shopping

James Allen Zoom

This brings us to shopping wisely. 2017 has introduced a new wave of high tech gadgetry; the same goes for diamond shopping! Gone are the days when brick and mortar stores are the ultimate go-to for engagement rings.

These days, it’s digital diamond shops like James Allen that ride with the times. They’re my current favorite as they make diamond hunting so much easier with their 360° diamond display technology.

What is the average diamond size for an engagement ring

You can filter your search with different cuts, shapes, colors, clarity, and carat weight. Since my mission is to give accurate diamond information, I needed a tool that can scrutinize the diamond 4Cs.

It offered experts like me a professional tool – one that you can also use to learn more about diamonds – beyond the surface, even beyond the notorious carat weight.

Click here to browse through more than 3,000 0.90 Carat Diamonds!

If you need any help in choosing the right diamond just leave me a comment or drop me a mail!

I answer within 24 hours. 🙂



Sebastian Naturski loves to write about diamonds and share his knowledge with his readers.
When he is not working on his website he is studying law at Humboldt University of Berlin.
He has taken part in several international law competitions and likes to broaden his horizons.
His other big passion are languages. He is fluent in German, English, Polish and Japanese and got basic skills in French and Spanish as well.