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How Much Should You Pay for a Half Carat Diamond?

How Much Should You Pay for a Half Carat Diamond?

If you’re looking to buy a half carat diamond – perhaps for an engagement ring – then working out what a 'good' price is can be a minefield. Diamond prices vary wildly and half carat diamond prices are no exception. So how are you supposed to set a reasonable budget?

In this article, we’ll take a look at some of the factors that affect how much half-carat diamonds cost, as well as explain how you can find the best value half-carat diamonds your money can buy.

First, let’s get some pesky basics out of the way. Feel free to skip this bit if you already know about carats and what half of one is.

What exactly do we mean by half-carat?

A half carat diamond is one that weighs exactly 100mg (milligrams) – that is 1/10 of a gram.

You might have come across different ways of describing half a carat, such as:

  • half or ½ carat diamond
  • 0.5 or .5ct diamond
  • 50 point diamond (1 carat = 100 points)

All these terms mean exactly the same thing.

How big is a half-carat diamond?

It varies. The carat weight of a diamond actually tells you very little about its size, as size depends more on the shape of the diamond and the way it’s been cut.

For example: Imagine two icebergs, both weighing 100,000 tonnes. One is tall and narrow, with most of its weight underwater. The other is wide, with a shallow base. Viewed from the top (as diamonds are), the first iceberg will look much smaller than the second.

The same size variation is true of diamonds (except diamonds generally support fewer penguins). This means it’s very difficult to ascertain a diamond’s size from its carat weight.

Even so, we can say with some confidence that a nicely cut round brilliant half-carat diamond will be between 5.10 and 5.30mm wide.

Is a half-carat diamond big enough for an engagement ring?

Yes, absolutely. In fact, it’s a very good size for engagement rings – not too big and not too small. Just right, as Goldilocks would say. A large proportion of diamond engagement rings are around the half-carat mark.

Half carat diamonds are also perfect for diamond earrings as the pair together make a full carat (Kind of like “You complete me” for diamonds. Aaah).

Now let’s move on to the question of half-carat diamond prices.

Q: How much does a ½ carat diamond cost?
A: Not half as much as a 1-carat diamond!

Actually, that’s truer than you think. It’s cheaper to buy two half-carat diamonds than it is to buy one 1-carat diamond. That’s because bigger rough diamonds are much harder to find and mine in the wild.

And, if you haven’t already guessed, there’s no such thing as a simple answer to the question of how much half-carat diamonds cost. Diamonds don’t come with RRPs. That’s because carat weight isn't the only factor that determines the price. Quality is just as important, if not more. A 0.5 carat diamond with visible inclusions and a hint of colour will cost significantly less than one that’s flawless and absolutely colourless.

But you came here looking for a straight answer, so I'm going to try to provide one.

The ballpark answer

A quick search of the 320,000+ diamonds listed on our website today (yes, that's a brag and no, it wasn't meant to be subtle) reveals that our least expensive 0.5-carat diamond costs £420 (a cheeky Oval shaped diamond) and our most expensive half carat diamond costs £4005 (a very Brilliant Round).

So, the answer to your question “how much does a half-carat diamond cost” is somewhere between £420 and £4005. (But only if you’re asking on the day this article was written!)

That’s quite a price range. But it illustrates a point, which is that the price of a half-carat diamond can be whatever you want it to be. But that's probably not the answer you came here for... so if you ask the diamond guru's at Quality Diamonds, they will no doubt point you to a beautifully cut, sparkly, white, eye clean round brilliant diamond for around £1650.

Search for the highest quality half carat diamonds

Search for Half Carat Diamonds under £1500

A half-carat diamond for every pocket

The beauty of buying a diamond is that you never have to spend any more than you want to. That’s because each diamond is slightly different and they’re all arranged in an orderly fashion from least expensive to most. In fact, for any given budget there is a sparkling throng of potential diamond suitors vying for your attention, which gives you lots of delectable choices…

You might choose a diamond with the highest quality cut, or one that has excellent colour or clarity. Or you might focus on dimensions to get the biggest half-carat stone you can. (All of these things are not mutually exclusive, by the way.)

You could even choose a diamond that weighs less than half a carat…wait, what?

Oh yes, that’s the other important thing you need to know about diamond prices.

Why people who know about diamonds don’t buy half-carats

(Or 1 carat or 5 carats, for that matter.)

It’s a general rule that there’s more demand for diamonds that weigh exactly half a carat, or one carat, or five carats. Because of this, those diamonds cost more (meaning you pay a higher price per carat).

Diamond experts know that if you drop the carat weight just a little – from 0.50 carats to 0.46 carats, for example – you can save quite a lot of money without losing anything in appearance.

Here are two virtually identical diamond volunteers to demonstrate:

Diamond A, aka “Felicia”
Round Brilliant
0.50 carats
F colour
VVS2 clarity
Certified by GIA
9.47 DiamondScore

Diamond B, aka “Priscilla”
Round Brilliant
0.45 carats
F colour
VVS2 clarity
Certified by GIA
9.48 DiamondScore

As you can see, these diamonds are very alike. In fact, apart from a few very minor considerations (conversational skills are one, I think), they are exactly the same in all but carat weight. And in that, there’s just a five-point difference, which is around 0.1mm when viewing from the top. Yet Felicia will cost you £440 more than Priscilla.

Or to put it another way, Priscilla’s price per carat is £3122 (give or take a penny) and Felicia’s price per carat is £3690!

If you remember nothing else, remember this

  • There’s no such thing as a single price for half-carat diamonds
  • Price is based on quality as well as carat weight
  • Two half-carat diamonds will cost less than one 1-carat diamond
  • Save money by buying diamonds just below the half or whole carat mark

Ultimately, carat weight should not be your only consideration. Yes, you may be able to get a cheap half-carat diamond but if it’s poor quality (which it probably is) then what you’re essentially buying is very expensive, murky looking glass.

My advice is to use half a carat as your starting point, adjust your search a little to include diamonds that are 0.45 – 0.55 carats, and then use the Four C’s or our very handy DiamondScore to find the highest quality diamond that falls within your budget range.

And when you've done that, come back to tell me how much it cost :-)


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