If you are not sure of your ring size, measure your finger and size on ring mandrel.
Straighten and cut 6, 6 inch pieces of square wire and tape together in a bundle if needed. Find and mark the center or the wires. Place the center of the wires on the ring mandrel about half a size smaller than the finished ring. Bend the wires around the mandrel and twist to secure, hold firmly to prevent the ring from sliding on the mandrel and ending up too large.