Diamond Carat Weight Explained

The carat weight of a diamond essentially refers to the actual weight of the stone. The larger the carat weight, the bigger and more expensive the diamond. Carats and points measure a diamond’s weight. 100 points make up one carat (0.01 carat = l point). One carat is equal to 0.20 grams.

The carat weight of a diamond is also considered with the distance across the top of the diamond – measured in millimetres and with the diamond’s cut grade.

The distance across the top of the diamond is important, as it is how the diamond stone is viewed when set into a ring. The cut grade should be considered when choosing the carat weight of the diamond. When the diamond is cut with the proper proportions, the maximum sparkle and light reflects out the top of the diamond. The carat weight of a poorly cut diamond may be hidden towards the bottom of the diamond, which will make the diamond appear smaller than its actual carat weight.

It is easier to determine the carat weight of your desired diamond that will fit it with your budget, once you have chosen the cut, colour and clarity of the diamond.

Download Diamond carat size PDF chart

Important Information About Carat Weight

People tend to believe that diamonds of 1ct in weight are all the same size in mm width. This is not the case, as it’s important to consider the depth of the diamond too. For example, a well-made round diamond of 1ct in weight should measure between 6.4mm to 6.5mm in width.

However, it is possible to find round 1ct diamonds of 5.9mm in width. This would immediately indicate that the diamond is poorly made; this is not a diamond that Steven Stone would ever sell. Obviously the fact that the diamond is poorly made would make this less expensive than a well-made diamond. So when comparing diamond prices, please make sure you compare genuine like for like.

If you would like to purchase a 1ct diamond, but want to optimise your budget, we would recommend a 0.90ct round diamond which measures 6.25mm in width, which is the same physical size as an average 1ct diamond. Additionally, a well made 0.90ct diamond will still possess the same sparkle, fire and brilliance as the more expensive 1ct option. This buying and sizing approach applies to diamonds of any size.

If you would like additional guidance or help in choosing the perfect diamond for an engagement ring, wedding ring, or any piece of diamond jewellery, please do feel free to call our diamond experts on 0161 233 9977 or contact us via our online form.