How to Determine Carat Size

One carat is equal to 0.2 grams, and one diamond carat is divided into 100 points, meaning that 0.25 of a carat is 25 points or ¼ carat. The size dimension of a diamond for its weight is a good indicator of its value and desirability. For example, a 1ct round diamond would ideally measure around 6.5mm in diameter, a 1.5ct around 7.2mm and a 2ct diamond approximately 8mm. Ideal diamond dimensions are different for every diamond shape. Dimensions are a good indicator of how well a diamond has been cut for it to reflect the maximum amount of light.

Value of diamonds per carat

The value of diamonds per carat can vary massively depending on the other specifications. Carat weight has a large impact on a diamond’s value, along with cut, colour clarity and certification. This means that even two diamonds of the same carat weight will most likely differ drastically in value.

What to consider

It is important to consider carat and cut together when buying a diamond. A larger carat diamond with a poor cut grade can appear smaller than a diamond of the same size with a higher cut grade.

Ring Size Guide

So you have found the perfect diamond ring, but how do you find your ring size? Whether you are buying an engagement ring for your partner or a wedding ring for yourself, our ring size guide UK provides the best tips on how to measure ring size at home.

Ring size conversion chart

How To Measure Ring Size With String, Paper & Ruler

If you’re wondering how to measure ring size at home, there are creative steps you can take to find the right fit. When shopping for someone else, the best way to find their ring size is to ask them directly. If you're planning a surprise, get help from friends and family. They can ask without raising any eyebrows. You can also use our ring size print out to measure their existing rings to find their size. There are also several at-home methods you can use to find your ring size or your gift recipient's ring size. These methods require a few simple tools to find the right fit including a piece of string, a ruler, a pen and a piece of paper. The at-home method for how to measure ring size may also require a quick calculation to find the numeric size.

1. Wrap string or paper around the base of your finger.

2. Mark the point where the ends meet with a pen.

3. Measure the string or paper with a ruler (mm) then divide by 3.14 (or Pi) to get the diameter of the ring.

4. Pick the closest measurement on the ring size chart to find your ring size.