Ring Size Converter

How to measure

Best: take a ring that fits the intended finger and measure its inside diameter with a ruler or calipers, edge to edge at the widest point. Good: wrap a strip of paper or a piece of string snugly around the base of the finger, mark where it overlaps and measure the length; that is the circumference. Measure at the end of the day when fingers are largest, and at room temperature.

Rules of fit

A ring should slide over the knuckle with slight resistance and sit without spinning. Wide bands (over 6 mm) need a quarter to half size larger. Large knuckles: size for the knuckle and add sizing beads inside if the ring spins. Sizing up is easier than sizing down for plain bands; pavé and eternity bands are hard or impossible to resize, so measure twice.