If you’ve heard the terms “carat weight” and “total carat weight” when referring to diamonds but you are not sure how these two concepts differ, read on. If you are considering buying a diamond ring, for example, you should know what its advertised carat weight really means.
What Is Diamond Carat Weight?
The weight of diamonds is measured in carats. One carat is equal to 200 milligrams (0.2 grams). Carats are further divided into points, and one point represents one hundredth of a carat; or, in other words, one carat contains 100 points.

Total Carat Weight is the sum of the individual carat weights of all diamonds in a piece of jewelry.
Diamond carat is abbreviated “ct” (or “CT”)as in 1 ct; you can also see carat weight denoted by “cw” or “CW.”
Another abbreviation used for the same thing is “dw” (or “DW”), which means “diamond weight.”
Diamonds of the same carat weight do not necessarily look the same size.
How big a diamond will look also depends on the proportions of its cut and on the setting that the stone is mounted in.
What Is Total Carat Weight and How Is It Different?
Total carat weight is a term that often confuses customers as they mistakenly assume that it means the same as carat weight.
Remember: Carat Weight is used to refer to the weight of a single diamond.
Total Carat Weight, on the other hand, is used to mean the sum of the individual carat weights of all diamonds in a piece of jewelry.
So, how is total carat weight denoted? The most widely used abbreviations are “ctw” (or “CTW”), or just TW, and “dtw” (or “DTW”), which means “diamond total weight.”
For example, if you are told that a ring has one diamond that is 1 ct and two smaller ones that are 0.5 ct each, then the piece will have a total carat weight of two carats and will be advertised as a ring of 2 CTW.
Alternatively, if a ring is labeled as being 1 CTW on its price tag, this means that the sum of the weights of all diamonds in it totals to 1 carat, but this information tells you nothing about the exact weight of any single stone.
If you look at each of these diamond rings and click on any one for details, you will see that its specifications list the weight of its diamonds as “total carat” — the same thing as CTW/DTW.
Important Questions to Ask When Buying
If you are buying a piece of jewelry with diamonds and there is a center stone (the biggest diamond), you should specifically ask about the individual carat weight of that diamond.
The central stone is the most visible one and is usually of the highest quality compared with the smaller diamonds in the setting.
That’s why the central stone will often be the diamond with the most weight in the price of the ring, and knowing this diamond’s carat weight will allow you to figure out how good of a deal you are getting.
The next question you should ask is: What are the carat weights of the smaller diamonds in the ring (also called “diamond accents”)?
These stones are often of lower quality as they are not as visible as the central stone. Knowing the carat weights of the center stone and the diamond accents will allow you to compare different rings and choose the best price.
For example, a ring with 10 small stones and a CTW of 2 ct is not comparable to one that has the same CTW of 2 ct but has one big stone and two smaller ones. Usually, bigger diamonds cost disproportionately more than smaller stones of similar quality.
Also, the bigger stone in the second ring is likely to have better color, cut and clarity as a central stone than each of the 10 small stones in the first ring.
If that’s really the case, you shouldn’t be paying the same price for the first ring just because it has the same CTW (assuming all other characteristics of both rings, such as metals and settings, are comparable).
In sum, when you see the total carat weight on the label of a piece of jewelry you like, always ask for a breakdown of this value by single stones, if that information is not listed.
Check out these diamond ring settings and see how they are priced depending on what kinds of diamonds they contain and how big the stones are.
Diamond Carats and Prices
When looking at diamond prices, you should keep in mind that bigger stones are much rarer to find than smaller ones of the same quality.
That’s why, as stones in a given quality range go up in size, their prices rise by an even greater factor.
For instance, a 2 ct diamond is not twice as expensive as a 1 ct stone of the same quality, but the actual price can be more than three or four times higher.
To see prices for diamonds of different carat weight, check out this loose diamond search engine, in which you can search diamonds by carat, color, clarity, and cut.
Remember to compare diamonds with similar characteristics. Differences in carat weight between two stones mean nothing if their cut, color and clarity are dramatically different.
Where to Buy Diamond Jewelry?
We recommend James Allen (read review) because you can see a 360-degree video for any diamond before buying it.
Blue Nile is another reputable diamond retailer we recommend.