Skip to main content

Carat Weight

May 29th, 2018

hearts on fire diamond-480x480Carats are the unit by which diamonds and other gemstones are measured (not to be confused with karats—click here to read our last post for more about the gold karats).

Though carats can often give an indication of the size of a diamond, carats are not a measurement of dimensions but are actually measurement of weight. A carat is equal to 200 milligrams and are measured exactly to the 100th of a carat and each 100th is called a point. While carat weight can give you a rough idea of around how large a stone will be, it's important to realize that the cut of the stone can vary the diamond size without changing the weight.

For example, two round diamonds both weighing one carat may appear to be entirely different sizes because of the depth of the cut. A more shallow cut will give the illusion of a bigger stone, but at the expense of losing some sparkle. A better cut, though it may appear smaller, allows more light in and has more sparkle than a shallow cut diamond of the same weight.

Screen Shot 2018-05-24 at 12.17.54 PM

Additionally, different shaped cuts will create different sized diamonds though two cuts may be the same carat weight. For example, oval, marquise, pear and emerald cut stones will often appear larger than their round and princess cut counterparts because of their elongated shapes. The different length x width ratios can also vary between shapes so two ovals of equal weights could appear to be different sizes as well.


Because it is impossible to know exactly how large a diamond will be just based on carat weight, it is important to always see your stones in person before purchasing. When you shop for a diamond at Gerald Peters, we make sure to show you a variety of diamonds within your style and budget to make sure you feel confident about the stone you are choosing. Though carat weight and all the other specs on paper are a great place to start in choosing a diamond, only seeing it for yourself will let you know how beautiful it really is.