What does the numbers for haircuts mean?

The numbers for haircuts typically refer to the length of hair left after cutting, expressed in inches or millimeters. For example, a "number 1" haircut usually leaves about 1/8 inch of hair, while a "number 4" leaves about half an inch. These numbers are common in clipper guards and help standardize the length of cuts across different barbers and stylists. Understanding these numbers allows clients to communicate their desired hair length effectively.