There are several ways to find out your ring size if you already have a ring that fits you well. You can measure your ring size using either string or perhaps a more common item in your home floss.
Mark the point where the ends meet with a pen.
How to measure ring size. Take one of these measurement tools and wrap it around the base of your finger marking where the string or floss first overlaps with a pen. Then line that up with a ruler and take down its length in millimeters. Measure your ring size with these steps.
Start by cutting out a strip of paper that is approximately 3 4 inch wide and 4 inches long. Pick the closest measurement on the ring size chart to find your ring size. Wrap string or paper around the base of your finger.
Measure the string or paper with a ruler mm. One of the easiest ways to assess your ring size is to measure your finger with a strip of paper or string. To find your ring size wrap a flexible measuring tape around the widest part of your finger near the knuckle.
You can also compare your ring to a printed out ring size chart in which you find the circle size that best matches your ring. Bring it to a jeweler to measure or slip the ring onto a mandrel to determine the size. Wrap the paper around the base of the intended finger and then mark where the paper overlaps.
Aim for a snug but comfortable fit and make sure to measure the exact finger where you plan to wear the ring since even the same finger on different hands can be different sizes.