Diamond Carat Weight (The 4 C's)

Diamond Carat Weight – (The 4 C's)

I'm not going to bore you with too much technical stuff, but if you are interested in buying some diamond jewelry you will no doubt have heard, and certainly need to know, what the carat weight of a diamond means . This should not to be confused with gold karat or carrots J (believe me I get this a lot!). It is also not the size… although size and weight are of course related.

If you would like to read about the history and metrics of a carat, good old Wikipedia is great: http://en.wikipedia.org/wiki/Carat_(mass). One thing that is good to know is that the term "points" refers to 0.01 carat… so 100 points make 1 full carat.

The carat weight of a diamond is one of the most significant factors that will affect the price of your rock; however I have a few tips that can help you save big.

A well cut diamond (I'll speak about cut later) will mean that for example a 1.00 carat round diamond will have a diameter of approximately 6.5mm.  A slightly deep cut diamond of the same carat weight can make the diameter smaller. "Under-sizes" are slightly less popular diamonds that are very close to very popular (and much more expensive carat weights). For example, you can save up to 50% by choosing a 0.95 carat diamond over a 1.00 carat diamond, despite them looking exactly the same without measuring.  In some cases, the diameter would be exactly the same.  Some examples include 0.45-0.49 carat instead of a 1/2 carat… 0.70-0.74 carat instead of 3/4 carat and so on. Over-sizes will have the reverse effect – you will be paying more in total for a diamond that is just a fraction heavier, but is not visibly larger.

Diamond prices in wholesale are referred to in terms of price per carat (or ppc). As the price per carat for a diamond increases, the larger the diamond, prices become exponentially higher the further you go. For example, a 0.50 carat diamond can cost $2000 ppc, meaning $1000 for the stone. A 1.00 carat diamond can be say double in price per carat at $4000, but will be 4 times the price for the stone.

Lingo summary for diamond carat weight:

100 points = 1.00 carat

Under-size = a few points below the most popular sizes (usually will look the same, but cost much less)

Under-size = a few points below the most popular sizes (usually will look the same but cost a bit more)

PPC = Price per carat

Ct. = Carat


If you would like to know any other sizes, just ask me. Fancy shapes don't really have a standard as it will depend on the length-width ratio, but I would happily help out.