Total Carat Weight in Diamond Jewellery Explained

Diamond jewellery listings often state a single carat weight, such as 0.50 carat for a pair of earrings. That figure is usually the total carat weight, or TCW. It is easy to misread, so it is worth understanding.

What TCW means

Total carat weight is the combined weight of all the diamonds in a piece. For a pair of earrings, it is the weight of both stones together. For a pendant with a cluster, it is the weight of every stone in the cluster. For a ring with a centre stone and a halo, it is the centre plus all the small stones.

Why it can mislead

A TCW of 1.00 carat can describe very different things:

• one 1.00 carat stone,
• two stones of 0.50 carat each, or
• forty tiny stones adding up to 1.00 carat.

They look very different. A single 1-carat stone is about 6.5 mm across. Two 0.5-carat stones are about 5.1 mm each. Many tiny stones are each only a couple of millimetres, though together they make a broad sparkling surface. See carat weight vs diamond size.

Pairs of earrings

For studs, TCW refers to the pair. A pair described as 0.50 carat TCW has two stones of about 0.25 carat each, which are each about 4 mm across. If you wanted each earring to carry a half-carat stone, you would need a TCW of 1.00 carat. Check which is meant.

Comparing two pieces fairly

• Compare TCW, but also the number of stones.
• Compare the quality range for the stones. See melee diamonds.
• Compare the gold weight and the making charge.
• Compare the total price, not the price per carat alone.

Price per carat can fool you

In jewellery, the price covers metal and making as well as stones, so dividing the price by TCW does not give the cost of the diamonds. Use the itemised bill to see the value of the stones separately. See how to read a jewellery invoice line by line.

Where the information appears

TCW should appear on the product page and the invoice, with the number of stones and quality range. For solitaires, the certificate gives the exact weight of the one stone.

"Look of" weights

Some sellers describe a piece by the size it looks, using phrases such as "looks like 1 carat". Treat those as marketing and rely on the stated weights and measurements.

What is a good TCW?

There is no ideal figure. A small TCW piece such as a fine pendant can be graceful. A larger TCW suits statement pieces. Choose by how it looks on you and what the budget allows.

Questions to ask

1. Is the weight stated per stone or in total?
2. How many stones are there?
3. What is the quality range?
4. Can I see the stone details on the invoice?

A worked comparison

Suppose you are choosing between two pendants, both listed at 0.30 carat total weight. One has a single stone of 0.30 carat, about 4.3 mm across. The other has a cluster of 18 small stones. The cluster will look wider and more textured, while the single stone will look more focused and have an individual certificate. Neither is wrong. The numbers just describe different things.

Compare in person

Book an appointment to hold two pieces of the same TCW and see how they differ. Or browse our diamond earrings, where the details of each pair are listed.