Diamond Carat Weight - Size

Diamond Carat Weight

Its quite common, and actually quite sensible, to buy an engagement ring, that has a diamond with the largest Carat you can afford, and has excellent Cut, reasonable Colour and reasonable Clarity. Reasonable means, anything around H or I in colour, and anything around SI1 or VS2 in Clarity. VS2 is probably a necessary choice in diamonds above 1 carat in size. Colour and Clarity, provided they are above a certain threshold, are very difficult for people to notice, whereas Carat Size and Cut grade have a major impact on how a diamond appears.

On this page we will cover the following on diamond carat weight:

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What is Diamond Carat Size / Carat Weight?

So, what actually is a Carat? Well it might surprise you to know its a measure of weight and not of size. 1 Carat is approximately 0.2 grammes (0.00705 ounces). Of course, as the weight increases, so does the size. The diagram below shows approximately the relationship of weight to size, for diamonds cut in the traditional round-brilliant shape:

diamond carat size

Its very common for people to want a quarter carat, half carat, three-quarters carat or one carat diamonds. These specific sizes are commonly sought after and you can often buy a Diamond Engagement Ring just below those sizes at much cheaper prices. i.e. buy a ring with a 0.9 carat diamond instead of 1.0 carat diamond.

What's the difference? Carat Weight or Total Carat Weight

Total carat weight (ctw) is not the same as carat weight (ct):

  • Ct refers to the diamond carat weight of one single stone.
  • Ctw refers to the 'total carat weight' of a number of smaller diamonds.

This is important, because five 0.20 carat diamonds cost a few hundred dollars whereas a single large 1.00 carat diamond would cost thousands: one is much rarer than the other.

We have a number of diamond rings with many small diamonds, and these are not only good value, but actually ideal for people with very active lifestyles, someone who is more conservative or who or who has a job where a more flamboyant design would be simply inappropriate.

marquise engagement ring The Duchess Engagement Ring from our Signature Engagement Rings Collection.
platinum engagement ring The Ignite Engagement Ring from our Modena Engagement Rings Collection.

What Diamond Carat Weight should I buy?

Your budget plays a major role in what carat weight you should buy, here is the approximate budget for a round brilliant designer engagement ring with different carat weights:

  • 0.30 ct = approximately $2,500
  • 0.50 ct = approximately $3,500
  • 0.75 ct = approximately $5,000
  • 1.00 ct = approximately $10,000

The above budget amounts are approximate as diamond cut, diamond colour and diamond clarity also play a part in the value of diamond engagement rings.

See our Modena Engagement Rings Collection and Signature Engagement Rings Collection where you can change the diamond to suit your budget for any of our designer engagement rings.

What changes as Diamond Carat Size increases?

The size of the diamond has a big influence on the cost of the diamond, larger diamonds being much rarer than smaller ones.

Be more careful with the clarity as the carat weight increases. SI2 Clarity might be ok below 0.75 carats, but above that choose a VS2. Above 1.5 carats choose VS1. Perhaps move up a clarity level if buying a diamonds with large wide open faces, such as princess cut diamonds, emeralds or asschers and even marquises.

Let's Go Shopping

engagement rings online Hopefully we have covered all the important things you need to know about engagement rings. If you still have any questions, please use the enquire button at the top of the page.


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