Here is a simple method for measuring your finger to find the correct ring size.
No method is as completely as accurate as actually trying on the ring,
this is a good way to start. Your local jeweler can resize
your ring for you. Remember that hands tend to swell at
times. This means that rings will fit differently on any given day and at various
times of the day. Rings should be snug while allowing sufficient space for
changes in fingers size.
Easy Method
Cut a strip of paper no wider than 1/4" .
Wrap the paper snugly around your finger and mark the paper where it meets.
Measure the marked length of paper and compare it to the chart below for the correct ring size.
If the knuckle is significantly larger than the base of the finger, measure the knuckle to ensure the ring will fit over it. This may make the ring very loose on the finger.