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Diamond Weight Abbreviations Chart
When reading diamond weights, it's important to understand whether you're looking at the weight of a single diamond (measured in ct) or the combined total weight of multiple diamonds (ctw, cttw, or tw).
- Single-gem jewelry — like a solitaire engagement ring or a solitaire pendant — will list the diamond's weight in carats (ct). This helps you evaluate the size and value of one focal diamond, often the centerpiece of the design.
- Multi-gem jewelry — such as tennis bracelets, halo engagement rings, or pavé settings — will use total carat weight terms like cttw, ctw, or tw, referring to the combined weight of all diamonds used in the piece.
Understanding this distinction ensures you know whether you’re buying one significant diamond or a piece made of many smaller ones. Brilliant Earth uses “ct. tw." but other retailers may use CTW, CTTW, or TW depending on their formatting preferences, but they typically refer to the same concept — combined diamond carat weight.
Abbreviation | Stands For | Meaning | Includes Center Stone? | Includes Accent Stones? |
|---|---|---|---|---|
CT | Carat | Weight of a single diamond | Yes | No |
CTW / CTTW | Carat Total Weight | Total combined weight of all diamonds | Yes | Yes |
TW | Total Weight | Usually total diamond weight, but may include other gemstones | Yes | Yes |
CT Meaning
CT, short for carat, refers to the weight of a single diamond. Not to be confused with CTW or CTTW, CT is a unit of measurement equal to 200 milligrams and is often used to describe the main center diamond in an engagement ring or solitaire pendant necklace.
CT Examples:
- 1.00 ct ring: A ring featuring a single diamond weighing 1.00 carat.
- 1.00 ct earrings: Sold as “0.50 ct each” means each earring contains a single 0.50 ct diamond, totaling 1.00 ct for the pair.
- 1.00 ct necklace: A necklace featuring a single diamond weighing 1.00 ct.
- 1.00 ct bracelet: A bracelet featuring a single diamond weighing 1.00 ct.
Want to learn more about how carat impacts diamond value and size? Read our Diamond Carat Guide.
CTW Meaning
CTW stands for Carat Total Weight. It refers to the combined weight of all diamonds in a piece of jewelry, not just one diamond. This includes the center diamond and any accent diamonds. This term is commonly used in jewelry pieces with multiple diamonds, such as three-stone engagement rings, eternity wedding bands, tennis necklaces, and earrings.
CTW Examples:
- 1.00 ctw three-stone engagement ring: A ring with a 0.70 ct center diamond and two 0.15 ct side diamonds, totaling 1.00 carat.
- 1.00 ctw diamond stud earrings: Each earring features a 0.50 ct diamond, totaling 1.00 carat for the pair.
- 1.00 ctw tennis necklace: A necklace with dozens of small diamonds that together add up to 1.00 carat.
- 1.00 ctw tennis bracelet: A bracelet with with dozens of small diamonds that together add up to 1.00 carat.
One of the most common errors is assuming that 1.00 ctw means there’s a 1.00 ct diamond in the piece. In reality, it may be a cluster of smaller diamonds equaling 1.00 ctw, two 0.50 ct diamonds (e.g., in stud earrings), or a 0.70 ct center with 0.30 ct side diamonds.
CTTW Meaning
CTTW also stands for Carat Total Weight. It is interchangeable with CTW, though some jewelers prefer one abbreviation over the other. Both refer to the combined weight of all diamonds in a piece.
CTTW Examples:
- 1.00 cttw three-stone engagement ring: A ring with a 0.70 ct center diamond and two 0.15 ct side diamonds, totaling 1.00 carat.
- 1.00 cttw diamond stud earrings: Each earring features a 0.50 ct diamond, totaling 1.00 carat for the pair.
- 1.00 cttw tennis necklace: A necklace with dozens of small diamonds that together add up to 1.00 carat.
- 1.00 cttw tennis bracelet: A bracelet with dozens of small diamonds that together add up to 1.00 carat.
One of the most common errors is assuming that 1.00 cttw means there’s a 1.00 ct diamond in the piece. In reality, it may be a cluster of smaller diamonds equaling 1.00 cttw, two 0.50 ct diamonds (e.g., in stud earrings), or a 0.70 ct center with 0.30 ct side diamonds.
TW Meaning
TW means Total Weight and is often used in the same context as CTTW or CTW — to describe the total diamond weight of all diamonds in a jewelry piece. However, in some cases, TW may also include other gemstones in addition to diamonds. Always confirm with the retailer if TW refers strictly to diamonds or if it includes other gemstone types.
- 1.00 tw three-stone engagement ring: A ring with a 0.70 ct center stone and two 0.15 ct side stones, totaling 1.00 carat.
- 1.00 tw diamond stud earrings: Each earring features a 0.50 ct stone, totaling 1.00 carat for the pair.
- 1.00 tw tennis necklace: A necklace with dozens of small stones that together add up to 1.00 carat.
- 1.00 tw tennis bracelet: A bracelet with dozens of small stones that together add up to 1.00 carat.
One of the most common errors is assuming that 1.00 tw means there’s a 1.00 ct stone in the piece. In reality, it may be a cluster of smaller stones equaling 1.00 tw, two 0.50 ct stones (e.g., in stud earrings), or a 0.70 ct center stone with 0.30 ct side stones.
FAQ
Is CTTW the same as CT?
No. CT refers to a single diamond’s weight. CTTW is the total weight of all diamonds in the piece.
Is CTTW divided between both earrings?
Yes. A 1.00 cttw pair of earrings usually contains 0.50 ct per earring, unless otherwise stated.
Does TW include the center stone in an engagement ring?
Usually, yes. TW includes the center stone and any accent stones unless specified otherwise.
Is there a difference between TW and CTW?
They’re often used interchangeably, but TW may include other gemstones, while CTW specifically refers to diamonds.
Can I tell how big the diamonds are from CTTW?
Not exactly. You’ll need to know how many stones make up the total weight. A 1.00 cttw ring with 10 small diamonds will look very different than a ring with one 1.00 ct diamond.
Is there a price difference between 1 CTTW and 1 CT?
Yes. A common misconception is that 1.00 cttw and 1.00 ct mean the same thing in value. They do not.
- A 1.00 ct single diamond is significantly more rare and valuable than several smaller diamonds totaling 1.00 cttw.
- Larger diamonds increase in price exponentially with size, due to their rarity. For example, a 1.00 ct diamond won't cost the same as two .50 ct diamonds, it could cost 3x or more depending on its diamond quality grades.
The visual impact also isn’t 1:1. Depending on quality grades, one larger diamond could have greater brilliance than a series of smaller stones totaling the same carat weight. And vice versa.
