Carat weight specifically refers to a diamond’s weight; however, by itself it may not accurately reflect size. It is also important to consider a diamond’s cut grade because when a diamond is cut with the proper proportions, the maximum amount of light or sparkle is returned out of the top of the diamond. If a diamond is cut well, the light reflected out of the top makes it appear larger. But if a diamond is poorly cut, much of the weight may be hidden in the base of the diamond, making the diamond appear smaller than its carat weight would imply.
For example, a diamond of a lower carat weight and higher cut grade can actually appear larger than a diamond with a larger carat weight but poor cut.