Carat is one of the 4Cs of diamonds that plays a significant role in determining their value. This is because a diamond’s value increases with its weight in carats. You may witness the cost of a solitaire engagement ring is often heavily influenced by the diamond’s carat weight.
However, have you ever wondered how diamond stores measure carats or the meaning behind the term “carat”? What is the correlation between diamond weight and carat size? In this article, we’ll provide you with answers to these questions.
Carats and Diamond Size
Although often used interchangeably, diamond size and carat weight are distinct characteristics. It is essential to understand the difference between them to determine which one is more important when selecting a diamond. Let’s explore their dissimilarities.
What is carat weight?
The weight of diamonds is measured using a unit of measurement called a “carat”. It is a unit of mass equivalent to 200 milligrams. And each carat is further divided into 100 points for precise measurement.
When a diamond weighs less than one carat, a diamond expert may use the term “points” to describe its weight. For instance, a diamond weighing 0.25 carats may be referred to as a “twenty-five pointer.” However, when a diamond weighs more than one carat, its weight is expressed in carats and decimals. For example, a diamond weighing 1.08 carats would be described as “one point oh eight carats.” You can learn the terms by following the carat size chart below:
Size chart
We have displayed the diamond’s diameter mm to carat weight in the diamond size chart below. This chart is based on averages of round brilliant diamonds. For instance, a round diamond’s diameter of 9.00mm to a carat is 2.75ct on average.
| 4.0 mm | 0.25 ct |
| 5.1 mm | 0.5 ct |
| 5.8 mm | 0.75 ct |
| 6.4 mm | 1.0 ct |
| 6.9 mm | 1.25 ct |
| 7.3 mm | 1.5 ct |
| 7.7 mm | 1.75 ct |
| 8.1 mm | 2.0 ct |
| 8.5 mm | 2.25 ct |
| 8.9 mm | 2.5 ct |
| 9.0 mm | 2.75 ct |
| 9.3 mm | 3.0 ct |
| 9.5 mm | 3.25 ct |
| 9.75 mm | 3.5 ct |
| 9.9 mm | 3.75 ct |
| 10.1 mm | 4.0 ct |
| 10.43 mm | 4.25 ct |
| 10.63 mm | 4.5 ct |
| 10.83 mm | 4.75 ct |
| 11.01 mm | 5.0 ct |
Assuming all other factors are constant, the price of a diamond tends to rise with its carat weight as larger diamonds are scarcer and more coveted. Nonetheless, two diamonds with the same carat weight may vary significantly in value (and cost) based on three additional characteristics of the diamond’s 4Cs: Cut, Clarity, and Color.
How Diamond Size Is Defined
In general, when we talk about diamond size, we are referring to the dimensions of the stone, including its height and width, as well as the measurements of its significant components.
Remember: Carat Weight Is Not the Same as the Size
The definitions of carat and size demonstrate that they are not interchangeable terms. Carat weight is solely concerned with the weight of a diamond, while size encompasses its dimensions.
Therefore, two diamonds with the same carat weight may have different sizes due to variations in their dimensions. Click here to know how you can calculate the exact carat weight of a diamond.
Similarly, diamonds with identical width or depth may have different carat weights, highlighting the difference between the two characteristics.
So does the carat affect diamond size?
Although it is generally true that a higher-carat-weight diamond will appear larger than a lower-carat-weight diamond, it is not always the case.
To accurately assess a diamond’s size, it is crucial to consider its measurements during your search. A well-proportioned 0.97-carat diamond may appear larger and be less expensive than a 1.00-carat diamond.
This is especially true for fancy-cut diamonds, which have less specific facet patterns and can result in varying sizes for diamonds with similar carat weights.
In conclusion, understanding the concept of carat weight in diamonds is essential when selecting suitable diamonds. It significantly impacts its value. While carat weight and diamond size are often used interchangeably, they are distinct characteristics that should not be confused. While a higher carat weight may result in a larger diamond, other factors such as cut, clarity, and colour can also affect a diamond’s value and appearance. Therefore, it is crucial to consider a diamond’s measurements, along with its carat weight, when determining its size and overall value.