Diamond CTW: What Does It Mean?

When shopping for diamond jewelry, you may see the abbreviation CTW and wonder what it actually means. CTW stands for Carat Total Weight, and it’s an important term to understand when comparing diamond rings, bracelets, earrings, and necklaces.

What Is Carat Total Weight (CTW)?

A carat is a unit of weight used for gemstones. One carat equals 0.2 grams.
Carat Total Weight (CTW) refers to the combined weight of all diamonds set in a single piece of jewelry—not just the largest or center stone.

Example of CTW in Jewelry

Imagine a diamond ring with:

• 1.00-carat center diamond

• 8 surrounding diamonds, each weighing 0.125 carats

• 4 side diamonds, also 0.125 carats each

Here’s how the total weight adds up:

• Center stone: 1.00 carat

• Surrounding stones: 8 × 0.125 = 1.00 carat

• Side stones: 4 × 0.125 = 0.50 carat

Total CTW = 2.50 carats

This means the ring would be described as 2.50 CTW, even though no single diamond weighs 2.5 carats.

How CTW Relates to Grams

Because one carat equals 0.2 grams, you can convert CTW to grams:

2.50 carats × 0.2 = 0.50 grams total diamond weight

Other Terms You May See Instead of CTW

CTW may appear in different forms, all meaning the same thing:

• TW – Total Weight

• DTW – Diamond Total Weight

These designations all refer to the combined diamond weight.

Carat vs. Karat: Don’t Confuse the Two

Although they sound alike, carat and karat mean very different things:

• Carat (ct): Weight of gemstones (diamonds)

• Karat (K): Purity of gold (e.g., 14K gold is 58.3% pure gold)

A ring can be 2.00 CTW diamonds set in 14K gold—both measurements matter, but they describe different materials.

Why CTW Matters When Buying Diamond Jewelry

CTW helps you:

• Compare jewelry pieces fairly

• Estimate price per carat

• Understand how diamond weight is distributed

However, CTW alone does not determine value. A piece with many small diamonds may have the same CTW as one with a single large diamond—but the larger stone is usually worth more due to rarity, cut quality, and visual impact.

Factors That Matter Along with CTW:

• Diamond cut

• Color and clarity

• Size of individual stones

• Overall design and craftsmanship

Final Thoughts

Carat Total Weight is a useful metric, but it’s just one piece of the puzzle. Understanding CTW helps you shop smarter, compare prices accurately, and avoid confusion when evaluating diamond jewelry.

When buying diamonds, always consider how the weight is distributed, not just the CTW number—and don’t hesitate to ask questions before making your purchase.