The average man's ring size is 10. The most common ring sizes for men fall into a range between 8 and 12. However, some individuals fall outside this span.
One way to determine ring size is with a ring sizer set. This is a group of plastic or metal rings in a wide range of sizes, typically 4 to 13, including half sizes. An individual tries any number of rings in the set until one feels comfortable. A metric measuring tape is also used to find the correct size. The tape is placed close around the base of the finger, but it must be loose enough to slide over the knuckle. The circumference of a size 10 ring is 62.2 millimeters.