37+ 1/8 Inch Hair Length

So why should the hair be this length and not shorter or longer?

37+ 1/8 Inch Hair Length. As the numbers increase, so too does the length of the haircut. A number 3 haircut cut to 3/8 inch;

What Are 8 Inch Hair Extensions You Worry That Your Hair Is Thin And By Beequeen Hair Medium
What Are 8 Inch Hair Extensions You Worry That Your Hair Is Thin And By Beequeen Hair Medium from miro.medium.com
One elbow length, or the distance from your bent elbow to the tips of your fingers, is 15 to 18 inches (35 to 48 cm) for most people. A number 0 is cut without a guard and is essentially a shaved look (1/16 inch of hair left). So why should the hair be this length and not shorter or longer?

Blick brush size chart 24 (11/16) 20 (9/16) flat, bright, filbert, egbert brush width chart.

A number 3 haircut cut to 3/8 inch; The length of an individual hair of the sideburn will not exceed 1/8 inch when fully extended. Hair which protrudes from beneath properly worn headgear in an unsightly manner is considered excessive regardless of length. Check the length of your arm against a ruler or measuring tape to find out how close to 1 meter this distance is for you.