Millimeters to hair widths equation
To convert millimeters to hair widths:
Multiply the number of millimeters by 0.005672922008668225
About millimeters
One millimeter is equal to a thousandth meters
About hair widths
A human hair's width varies between 17 and 181 micrometers. The measurement used here is 144th of an inch — around 176 micrometers — it was sometimes used with English units, but is not included in the Imperial system.