When Would I Notice Size Differences in Carat Weights?

What carat size should I choose? Would I be able to notice a difference between 2 diamonds that are 0.3 mm apart? When would I start noticing size differences physically with diamonds from various carat weight brackets?

layout of different types of diamond shapes

If you are one of the people with these questions in mind, don’t worry, it’s very common. I get asked these questions frequently via emails and decided to create this blog post to answer them.

First things first, let’s address why people ask these questions. The underlying reason is always related to cost and when we are talking about thousands of dollars, I’m sure everybody wants to make a purchase that offers best value for money.

Diamond prices jump at every 10 points. For example, a 0.50 carat diamond would cost about 40% more than a 0.40 carat diamond of similar specifications. However, the real difference in size between these 2 stones is roughly 0.4mm. And if you pick up a ruler and look at the subdivisions, a 0.4mm difference might not be that big of a size difference.

how does 1 mm look like

Ruler showing 1mm markings

To help with visualization of different sizes, we’ve compiled a printable chart of real-life diamond sizes and their relative carat weights. Click here to check it out and download a copy in .pdf format.

The Key Question Is: Can You Tell The Differences?

Weird as it seems, people tend to notice the 0.4mm difference when comparing objects of smaller sizes. When comparing bigger objects, our brains seem to perceive the same difference as insignificant. Let me show you some examples to illustrate this…

size difference between .4 carat and .5 carat4.8mm – 5.2mm

Do you see the differences? Most people do when they compare a 0.40 carat diamond against a 0.50 carat diamond.

size difference between 1.50carat and 1.75 carat

7.4mm – 7.8mm

In contrast, the same physical difference between a 1.50 carat diamond and 1.75 carat diamond isn’t readily detected because of the way our brain works.

Here Are a Few Other Examples to Check Out…


size difference between 0.9 carat and 1.0 carat

6.2mm – 6.5mm

Also, what happens if I pull the same diamonds further apart from each other?


further apart



comparison at a distance


Do you realize it is harder to notice size difference now? In real life, most people casually observe diamonds from a distance and it isn’t easy for them to pick up minute differences.

Now, most people buy diamonds within the 0.50 – 0.75 carat ranges. If you do a comparison using the image below, I think it is pretty clear that you would notice a difference.

size difference between carats of 0.50 and 0.755.2 mm – 5.8mm

Ultimately, Your Opinion Is What Matters Most!

So, what do you think? Perception is more of a subjective matter than an objective one. Some people see differences in sizes easily and some don’t. It is the same with diamond colors where individuals can see clear differences between F and G color diamonds whereas the majority of us don’t.

I know of people who are psychologically affected by the size of the diamond in their minds. Even if they are wearing a 0.92 carat diamond, in their mind, it is never good enough unless it is a 1 carat diamond.

Go for a carat size that’s “mind-clean” and affordable to your wallet. After all, diamonds are purchases which are meant to be enjoyed instead of being something that constantly frets you at the back of your mind.

If you are looking for a diamond that is cut to the best standards and optimal light performance, I recommend checking out Whiteflash and Brian Gavin. Their signature diamonds look spectacular in real life and represent the top 1% of well-cut diamonds in the market.

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  1. teresa-
    August 25, 2012 at 2:13 am

    what would be a fair price for a diamond with 0.53 carats, F color and VS2 clarity?

  2. Paul-
    August 25, 2012 at 9:18 am

    Unfortunately there is no way to tell with the limited information that you had posted.

    If possible, please include the shape of the stone and grading report in order for me to give you accurate advice.


  3. Ludmila Pechalová-
    September 14, 2012 at 5:01 am

    I am actually considering a split shank design for my new ring project. Are there any tips or advice that you would offer for one that would enhance the size of the center stone?

  4. Paul-
    September 16, 2012 at 10:32 am

    A halo setting would help greatly when done right.

    *edited comment for updates in blog*

    I had made a blog post on how different ring designs can help enhance the physical size of the center stone. It’s well worth your time checking it out here:


  5. Nicoline J. Karlsen-
    October 4, 2012 at 1:03 am

    Does this look like a good buy?

    Pear: 1.21 carat, 62% depth, 59% table, F color and VVS2 clarity.

    Thanks for the awesome website and your opinion on this stone…

  6. Paul-
    October 5, 2012 at 11:43 am

    Hi Nicoline,

    On paper, it seems like an OK choice. However, I won’t recommend buying a pear shaped based purely on paper. There are some aspects like bowties and light performance factors that a grading report won’t tell you.

    Please read the following links for more details:


    Feel free to bump me an email if you have further questions.

  7. Modi-
    April 24, 2016 at 12:46 pm


    I was looking into diamonds and found this:
    Round cut, vvs2, g, very good cut, 0.92 carat. What’s a good ballpark price for a diamond with that specifications ?

  8. Paul Gian-
    April 24, 2016 at 3:21 pm


    I will not pay a single cent for a diamond that’s poorly cut. And yes, Very Good is simply mediocre.

  9. Julia Santos-
    June 23, 2016 at 6:17 am

    Hello there. Should I get .80 round ideal cut, f , vvs2 or 1.18 round ideal cut, I, sl1 for $1,200 more?

  10. Paul Gian-
    June 23, 2016 at 6:26 am

    Depends on what your priorities are. Read this: https://beyond4cs.com/buying-diamonds-blind/

  11. Ken-
    August 14, 2016 at 10:30 am

    Am looking at 2 Round Brilliant Diamonds, one is 1.01 and another is 1.06 carats. Both are VVS1, D Colour, XXX cut/clarity etc. Help with prices pls? :)

  12. Paul Gian-
    August 14, 2016 at 3:34 pm

    There’s a link in the navigation tab under “Home” that explains prices in details.

  13. Stephen-
    October 8, 2016 at 12:11 pm

    Hi would you go for a .40 round brilliant Colour F Internaly flawless cut excellent or
    .50 colour H VS1 very good cut ??

  14. Paul Gian-
    October 8, 2016 at 2:56 pm

    Neither. The flawless clarity is a waste of money. The very good cut on the H diamond is just a turn off.

  15. Michelle-
    December 23, 2016 at 10:06 pm

    Hi Paul,
    I’m glad I found your site. Just curious regarding your answer to ” Hi would you go for a .40 round brilliant Colour F Internaly flawless cut excellent or .50 colour H VS1 very good cut ??”. Why do you say ” flawless clarity is a waste of money” ?

    I m considering buying an round, F, IF, excellent cut/ symmetry/ polish.

  16. Paul Gian-
    December 26, 2016 at 3:44 pm

    In reality, you won’t be able to see differences with the naked eyes between a VS diamond and an IF diamond. That’s why I think it is a waste of money unless you are looking for symbolic reasons for an internally flawless stone.

  17. cherri gibson-
    March 30, 2017 at 2:08 pm

    Hi there, i am looking at a tiffany. Vs1 and h in colour. All papers say excellent cut. It is platinum. But the stone is a tiny .21 on my large fingers. The seller wants £500! What do you think?

  18. Paul Gian-
    March 31, 2017 at 12:23 am

    This deal sounds dodgy to me because a real and original platinum setting from Tiffany & Co would cost more than £500. If the vendor has the original certificate and can prove that it is an authentic Tiffany ring, I think it is a decent buy. As for the diamond being small for your fingers, I’m not sure what kind of carat sizes you are expecting here. Are you expecting to get anything larger than 0.2 carats realistically with that budget range?

  19. Romayne-
    April 7, 2017 at 4:08 pm

    Hi Paul, Took your advice and checked out James Allen, love it! On the GIA reports, what refers to the cut? Is it the polish/symmetry characteristic? Is it better to have a higher grade on the polish or the symmetry or do both go together and should be excellent all around?

  20. Paul Gian-
    April 8, 2017 at 1:57 am

    Depends on the shape of diamond you are looking for. If you are looking for round brilliants, polish and symmetry would be important factors to keep at excellent ratings. For fancy shape diamonds, they aren’t necessarily that crucial and you will need other information such as videos/ASETs to help you determine cut quality.

  21. Glenn-
    April 24, 2017 at 5:16 pm

    Hi Paul,
    I am looking at two dianonds. Both Round, VVS2, D, Ideal, ME

    The difference is price and size

    .72 @ $2885
    .73 @ $3089

    I understand the difference while it looks good on paper cannot be differed using the naked eye.

    I guess my question is, is $200 extra worth it for that .01 size difference? Thanks.

  22. Paul Gian-
    April 25, 2017 at 12:14 pm

    I doubt the extra $200 accounts for the size increase. There are other factors at work here: https://beyond4cs.com/diamond-prices/

  23. Jerring-
    September 12, 2017 at 8:35 am

    Hi Paul,

    Is it worth to buy a 0.31 GIA certified internally flawless Ex Ex Ex cut grade in f colour or should I buy a bigger size with a bit less of the quality?


  24. Paul Gian-
    September 12, 2017 at 8:56 am

    Ask yourself, why do you need the IF clarity for? If you need it for symbolic reasons, by all means get the stone. Otherwise, you are just throwing your money away into an aspect that your eyes cannot appreciate.

  25. Brett-
    September 13, 2017 at 2:18 pm

    Hello Paul, I’m currently looking to buy a emerald cut diamond. If it wasn’t emerald cut I wouldn’t be as concerned with the clarity and color. Currently I am looking at VVS1 or higher, G or higher. Am I wasting money when I could go lower because all I’m concerned about is how it looks through the naked eye.

  26. Paul Gian-
    September 13, 2017 at 4:26 pm

    Depends on what carat size you are looking to buy. I would say that VS1s would be more than enough to ensure eyecleanliness.

  27. Keith-
    November 27, 2017 at 1:19 pm

    Hi Paul, I was thinking of buying a Cartier 1895 paved round dimond ring platinum, carat . 4ct Colour h, vs1 .. Price 4350 uk pounds do you consider that as best value for that type of ring?

  28. Paul Gian-
    November 28, 2017 at 2:21 am

    Putting value with branded goods is kind of an oxymoron. For such a small sized diamond ring and priced excessively at 4350 pounds, you can get a better cut diamond and setting at a quarter of those prices.


  29. lynn-
    January 5, 2018 at 12:40 am

    I would really like your advice, I am purchasing an eternity band. I am not sure if I should go with .40 f sl1 or go with .45 diamonds sl1. which one would have more spark.. Any advise is welcome ty Lynn

  30. Paul Gian-
    January 5, 2018 at 3:13 am

    Size is not the determining factor of whether a diamond will sparkle or not. Cut quality is. If you are looking for the best sparkle in an eternity ring, go to Brian Gavin or White Flash. They use super ideal cut diamonds for their melee stones.

  31. Jenan-
    February 10, 2018 at 1:47 am

    Hi there!

    We’re looking at one diamond that is VS2, round brilliant, 1.36 I and VS2 round brilliant, 1.46 J. These are comparably priced, and although I like the 1.46 size, the J color turns me off since I’m color sensitive (even though the cut is gorgeous).

    The alternative is VS2 round brilliant 1.54 G for around $2000 more. Is this good value? Or do you think there isn’t a big difference between 1.36 and 1.46 size if I’m satisfied with an I color?

  32. Paul Gian-
    February 10, 2018 at 4:35 am

    The ct weight differences will not be obvious ASSUMING these diamonds have identical cut quality (which I doubt so).

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