If you do not know your ring size, you can measure your finger using a regular thread (the thread can not be stretchable). Thread or thin string wrap around the widest part of the finger and cut or mark the place where the thread wraps your finger. The obtained thread length is measured with a ruler and converted to mm. Then divide these lengths in mm by 3.14 and you get the diameter of the ring. Find the result of your ring size in the table below.