How to Know Your True Ring Size — According to Jewelry Experts

The size of a finger is measured in millimeters (half sizes are separated by 0.4 mm and full sizes by 0.8 mm) to be as precise as possible. "Most fashion jewelry comes in whole and half sizes only, but in fine jewelry, we can get as fine as quarter sizes (6.75, 8.25, etc.), ensuring you have a really accurate fit," Brynne Overton, digital coordinator of Valerie Madison, told POPSUGAR. That means even the slightest fraction of size can affect the accuracy of the fit.