This is a chart that will be extremely helpful for you to determine the ring size that you need. You can either make use of a tape or a small piece of string to measure the area that will be occupied by the ring. When it becomes a complete circle, make a mark on such string. This will be helpful for you to compare with the chart that is mentioned below.
1: Print out the Ring Size guide and cut out the sizing tool. Slide the end tab of sizing tool through slot Ring Size Here vertical line and wrap the sizer around the base of the finger. Make sure to allow size for the knuckle. The number aligned with slot line is your ring size
2:Place a ring that fits intended finger you are shopping for on each circle until you find one that matches. The black circle should trace the inside of your ring.
3:To measure your finger using the reference chart: 1. Wrap a string around your finger. 2. Find the length of string that wraps around your finger exactly one time. 3. Measure that length of string against the closest circumference in chart.