Buyers can estimate ring size by themselves with 3 methods.

1.  Bring your ring over the guide of ring to find the right fit or compare it to the inside diameter (This method is the best accurancy)

2. Use the ring belt sizer for convenience and easily print at home to measure the right ring size yourself or as a gift.

Link to ring measurement  https://www.nksilver.com/form/381/form-d:-ring-measurement-

3. Use a string or ribbon to measure your finger, then put on the ruler to know the length of the ring circumference.