Quite simply, a diamond’s carat is a measurement of weight. One carat equals 1/5 of 1 gram (or 200 milligrams) and is based on 100 points, meaning .50 is a half-carat, .25 a quarter-carat etc.
Diamond carat weight is often associated with size, which does not always coincide, considering size is determined by the millimeter measurement across the top, which doesn’t take into the weight difference that comes from the cut type and the cut grade – which affect both shape and sparkle. Cut should always be taken into consideration when looking at a diamond’s carat weight. For example a diamond with a poor cut, may hide much of its carat weight in the base, appearing much smaller. Conversely, a diamond that is well cut, but a lower carat weight, may appear much larger.
A few gems of wisdom:
View and print our Diamond Carat Size Guide.