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A Beginner’s Guide to Carat Weight

A Beginner’s Guide to Carat Weight

Posted in: Diamonds

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When you start the hunt for a diamond engagement ring or wedding ring, you come to learn a lot about what’s involved in the process. You discover what sets the price, how to determine a diamond’s quality, and even where the best places to shop are. 

One significant part of the purchasing process can also involve carat weight. Keep reading to learn how carat weight plays a role in which beautiful new ring you purchase. 

What Is Carat Weight?

Carat weight may not make a lot of sense to people who have just started shopping for a diamond engagement ring. However, it can be essential to forming a bigger picture around what a quality diamond looks like.

Carat is a weight measurement of diamonds and gemstones. A single carat equals 200 milligrams or 0.2 grams. You will often see it written as ‘ct’. 

The term ‘carat’ comes from the carob tree’s fruit seed. The seeds of this tree’s fruit tend to be even in weight, so they were used in the Mediterranean basin as counterweights for performing balances. 

How Does a Diamond’s Carat Weight Affect Its Price?

It goes without saying that a heavier diamond comes with a higher price tag. Larger diamonds are also much rarer than smaller ones. But that’s not to say that the price tags are all relative to their carat weight or increase at a steady rate. 

You might assume that a 0.50-carat diamond would cost half as much as a one-carat diamond. Often, that’s not the case. Instead, a 1.0-carat diamond ring could cost three or four times as much as one half the weight, based on its size, rarity, and other factors. 

Does a Bigger Diamond Mean a Better Diamond?

You want the best for the love of your life. Still, a bigger diamond in your engagement ring doesn’t necessarily mean a better diamond. Instead, the carat weight is one factor of four that play a part in the decision-making process. 

The other factors you have to consider are cut, colour, and clarity. We’ll cover what these mean in greater detail below. 


The cut of a diamond refers to the quality of its finishing, facets, proportions, and angles. Often, the price tag is reflective of the cut. 


You might think that colour refers to coloured diamonds, but it actually refers to how colourless the diamond is. The more colourless they are, the more they can be worth. Colour grades are determined on a scale of D to F, G to J, K to M, and N to Z. 


The clarity of a diamond is determined by how ‘clean’ it is. The fewer inclusions and blemishes a diamond has, the more it is worth. 

How is Carat Weight Measured?

We know that 1.0 carat equals 200 milligrams or 0.2 grams, but how is a diamond weighed so that an accurate weight can be recorded? In most cases, a GIA laboratory uses electronic micro-balance scales. 

These scales can measure a diamond up to five decimal placings or a hundred-thousandth of a carat to ensure accuracy. However, you may only see a diamond engagement ring for sale using two decimal places up to a hundredth of a carat. The price of the diamond is then calculated by multiplying the weight of the carat by the price per carat. 

Carat Weight vs. Total Carat Weight

When you start browsing through the various pieces of jewellery online, you will notice that many beautiful rings have more than one diamond. How are you supposed to measure the carat weight when there is more than one diamond in a ring? 

The carat weight describes the weight of one stone, whereas the total carat weight (TCW) is the weight of all diamonds in a ring, if there is more than one. You may see the TCW of a ring advertised as 2.50 cts. That doesn’t mean one diamond is 2.50 cts. Instead, it may mean that the central diamond is 1.50 cts, and the halo of diamonds around it makes up the remaining weight. 

These smaller diamonds do contribute to the price tag of a diamond ring, but the centre stone tends to make the most significant impact on that price. 

How Do You Know the Carat Weight is Accurate?

When you start shopping online for a beautiful diamond engagement ring, you may wonder whether the carat weight is accurate. How can you be sure? 

When you shop with a reputable online or bricks-and-mortar jeweller, you may see something called a GIA Diamond Grading Report. This means that a GIA laboratory has assessed all four C’s of a diamond to determine its quality and how it’s reflected in the price tag. 

Are You Ready to Go Shopping?

You don’t need to have the most extensive diamond knowledge before you start shopping. However, it can certainly help when it comes to choosing the most beautiful diamond within your price range. 

This information above may prove useful for helping you make your decision. When you shop with reputable jewellers, you can also rest assured that they can assist with any other questions you may have. Why not start shopping today?

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