CTTW Meaning and And Why This Information is Important

Last Updated on September 19, 2023 by Juli "Jewels" Church

Do you know what the meaning of CTTW and why it's important to know when buying diamond jewelry? 

If not, you're in the right place. In this Learning Guide, I'll answer top questions about this jewelry acronym like:

cttw meaning
  • How much is a 1 cttw diamond ring?
  • Is carat weight and carat size the same thing?
  • What’s the meaning of cttw?

What is a Diamond Carat?

A carat is the weight measurement used for a diamond. Just like we use pounds on a scale in the US, we use carat weights for diamonds. One carat weighs one-fifth or .20 of a gram. It can also be seen as 200mg. Grams aren't used often in fine jewelry though.

Most people are familiar with using fractions for diamond carats. 1 carat, 3/4 carat, half-carat, one-third carat, and one-fourth are common carat weights for earrings and diamond rings.

And just like fractions, we can also see carat weight converted into carat points by using decimals. For example, 1/4 carats would be the equivalent to .25 carat points.

The word carat originates back to alternative methods of weighing precious stones of all sizes. Before carats, stones were measured by using carob seeds. These tiny seeds weigh about 200mg or one-fifth of a gram each, the same overall weight for one carat loose diamonds. This is how ancient civilizations measured larger diamonds, a smaller diamond, and even larger stones that aren't diamonds.

carob seeds

credited:  Roger Culos

Carat vs Karat

Diamond carat weight is not to be confused with karats for gold. These are two differ greatly. One is used for measuring the amount of gold content in a piece of jewelry and the other is used for weighing a loose diamond.

What Does 1 CTTW Mean in Jewelry?

If you've ever shopped at the local jewelry industry retailer at your neighborhood mall, you may have seen the acronym CTTW on the price tag of a diamond ring. You may have seen it in descriptions when shopping online.

In jewelry, CTTW stands for carat total weight (tw). The CT stands for carat and the TW stands for total weight. It can also be called total carat weight or total diamond weight, or carat weight total (ctw).

You may see it abbreviated as TW or TDW. CTTW, CTW, TW, and TDW all stand for the total combined weight of all the diamonds in a piece of jewelry. It could be an entire engagement ring or a single diamond.

Carat Weight vs Carat Total Weight

Understanding the difference between carat weight and total carat weight is key when buying your diamond engagement ring. A one carat solitaire diamond ring is not the same as a cluster diamond ring that weighs 1 carat in total.

Even though they have the same weight in total, the two rings couldn't be more different.

Let me explain.

In traditional solitaire rings, there is one center stone. There are no accent diamonds or any other stones in the setting. Newer solitaire ring styles may have hidden diamonds on the sides of the setting or encrusted on the prongs. However, these are usually very small diamonds.

hidden accent solitaire
hidden diamonds solitaire ring

For this comparison, we're just going to go with a classic solitaire engagement ring. The total diamond weight of this emerald cut diamond weighs 1 carat.

1 carat emerald solitaire

This ring is made up of several diamonds. When smaller stones are set closely together in the shape of a center stone, it is called a cluster setting.

The majority of Kay Jewelers' Now and Forever collection are cluster settings or quad settings, which is a cluster variation. Four square shaped small stones are set closely together to give the illusion of being a large diamond.

Cluster settings are a great way to afford a diamond ring because of the small diamonds set in the ring. You don't need the highest clarity or color grades for small accent diamonds. Technically, they're lesser quality because the grades are low, but a low total carat weight of each small diamond doesn't need to be VVS clarity.

The diamonds would be so small you couldn't even notice inclusions found in SI clarity diamonds. With lower grades and lower diamond total weight per small diamond, they're more affordable.

Now, if you had a 1/2 carat diamond as the center stone of your three stone ring and two side stones each weighing .25 carats TW, it may be on the more expensive side. A 1/4 total carat weight may require higher diamond grades than side stones weighing 1/10 ct tw each.

Total Carat Weight in Diamond Earrings

The total weight of a pair of diamond earrings can also be confusing. If you read 1 ctw on the price tag of a pair of diamond studs, it means that total weight (tw) of the diamonds in both earrings are equal to 1 ctw. With one diamond in each ear and a total weight of 1 carat, each stone would have to weigh .5 carats each, or a half-carat per diamond.

1 CTTW Cushion Earrings

Diamond Weight vs Diamond Size

You know that the carat weight of the diamond is how much the diamond weighs. Carat weight is equivalent to diamond weight. It can be the diamond total weight of one diamond, or the total weight of all diamonds in the setting.

Diamond weight is not the same as the diamond size. Likewise, the carat weight of one center diamond is not the carat size.

You still with me?

Diamonds come in many shapes. Round cut diamonds are the most popular. Because of their popularity, many customers are shown a carat weight chart showing an example of different carat weights of a diamond.

However, the diamond shape will determine the face-up size of your stone. For example, 1 carat tw round diamond will appear smaller than a one carat pear cut diamond with a total weight of 1 carat.

Though they weigh the same, the two diamond shapes require different cutting techniques for both shape and sparkle. More of the carat weight in a round diamond is distributed in the deep pavilion of the diamond.

A pear cut diamond isn't cut as shallow and it's an elongated shape. Or you can think about it in simple terms: a tear shape is bigger than a round shape. They may weigh the same, but the surface area size is different.


How Much is a 1 ct tw Diamond Ring?

A 1 ct tw diamond ring means the total carat weight of all diamonds in that ring is equal to total weight (tw) of one whole carat. The cost of a 1 ct tw diamond ring will depend on the details of both the diamonds and the ring setting. Other factors can also contribute, such as brand or diamond certification.


Diamonds are not valued nor graded on their carat weight alone. The quality of a diamond is determined by the 4Cs of the diamond. This grading scale was created by the Gemological Institute of America, the world's leading authority in all things diamonds and gemstones.

This scale is broken into 4 pillars: diamond cut, diamond clarity, diamond color, and diamond carat weight. Each tier is broken down further into grades, except carat weight.

The grades of a diamond is the biggest factor when determining the price of a diamond. However, the value can greatly increase or decrease, depending on the carat total weight of the diamond ring.

Smaller diamonds set in an engagement ring weighing 1 total carat weight will most likely cost less and have less value than a single center stone weighing 1 total carat weight.

If a single diamond has lower diamond grades, it may cost less than diamond jewelry with small diamonds equal to 1 carat total weight.

A single diamond usually costs more than a small diamond because it's easier for diamond cutters to cut smaller diamonds out of diamond rough. It's much harder for them to cut larger diamonds of high quality. Majority of rough diamonds mined are not gem-quality and are used for industrial purposes.

rough diamond

credited: James St. John

It is very difficult to cut a large diamond with excellent clarity and color grades. That is also why diamond prices are more expensive on a large central diamond than it is for many small diamonds with the same total weight.

Ring Setting

The ring setting of your 1 cttw diamond ring also contributes to its overall cost. If you are buying a single loose diamond, this won't apply to you.

But if your loose diamond has been set into a ring, the price will include the setting. Different ring metals have different values and prices. If your 1 ctw diamond ring is made of solid platinum or gold, it'll cost more. If it's sterling silver or a plated gold jewelry item, it'll cost less. Likewise, 14 karat gold will be cheaper than 18k gold rings.

Are TW Diamonds Real Diamonds?

Not every piece of jewelry that has a number plus CTTW, TW, or TDW is a diamond. Though this is how the jewelry industry measures diamonds, seller of other gemstones and diamond simulants may measure the stone as carats.

Officially, other gems are measured by millimeter weight. However, more customers are familiar with diamond carat weight, so it's easier to assume by carat weight than millimeter size for customers.

Even sparkly colorless stones may be measured as CT or CTTW. It can be misleading when a listing reads something like "1 ct tw diamond cubic zirconia". If it has the word cubic zirconia or CZ in the name, it is not a real diamond. Lab made diamonds in engagement rings are real diamonds also measured in carats.

Simulated diamonds and imitation diamonds are not diamonds. They are other colorless gemstones that can either be diamond alternatives, or diamond deceivers, depending on how they're disclosed to the buyer.

Is 1/10 CT tw Diamond Good?

Remember how carat weight of diamonds are measured in fractions and carat points (decimals)? That would make 1/10 of a carat .10 or 10% of 1 full carat.

A tenth of a 1 carat diamond is a very small diamond. Diamond weight weighing 1/10 ct tw can't be a center stone. Most retailers won't sell center stones smaller than .3 carat total weight.

Diamond jewelry with small diamond chips often weight around 1/10 of a carat total. Places like Kays and Zales give away cheap pieces of diamond jewelry items like that at their Customer Appreciation Events.

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