Diameter of a Human Hair
An educational, fair use website
| Bibliographic Entry | Result (w/surrounding text) |
Standardized Result |
|---|---|---|
| Piezo Technology. Epson (UK) Ltd. | "45 microns, 2 times smaller than the diameter of a human hair and close to the limit of resolution for the human eye" | 90 μm |
| Denny R's Homepage. Denny & Gayle Rossbach. Palmdale, CA. | "Diameter of a human hair inches: 0.001; centimeters: 0.00254" |
25.4 μm |
| Why Choose a Water Treatment System? Aqua-Fresh Drinking Water Systems, Inc. | "Particulate contaminants including asbestos, rust, sediment, dirt, and scale as small as 0.2 microns (1/300th diameter of a human hair)." | 60 μm |
| Hair - Important Facts About Hair. CAQTI Cosmetics, Inc. | "Flaxen hair is the finest, from 1/1500 to 1/500 of an inch in diameter… and black hair is the coarsest, from 1/450 to 1/140 of an inch." | 17–50 μm (flaxen) 56–181 μm (black) |
Hair can be found all over human body, except for the palms of hands and at the soles of feet. The purpose of hair is protective: the hairs on the body keeps a person warm, nose hairs prevent dust and dirt from entering the respiratory system, and eyebrows prevent sweat from entering the eyes.
The diameter of a human hair does not have a standard value since different people have different hair structures. Your genetic makeup can cause the width of your hair to differ from that of other people. Hair color is also a big factor. Black hair is thicker than is red hair. The weather can also affect the diameter of a hair strand. As the weather gets warmer, the diameter of body hair increases. Age is another factor. Babies and young children have finer hair than adults. As a person grows up, their hair becomes thicker and stronger. Another factor is that, the closer to the root of the hair, the thicker a strand of hair would be.
In my research, I have found the diameter of human hair to range from 17 to 181 μm (millionths of a meter).
Brian Ley -- 1999
| Bibliographic Entry | Result (w/surrounding text) |
Standardized Result |
|---|---|---|
| SEM image of the week: Only their hairdresser knows for sure. Mert Keçeli, Joanne Wen, Sara Saad, Glenn Elert. Midwood Science (7 November 2011). | [see images below] | 60~80 μm |
 |
 |
 |
 |
Editor's Supplement -- 2011
External links to this page:
- Single slit interference made easy with a strand of hair and a laser. Rebecca Messer. The Physics Teacher. Vol. 56 No. 1 (2018): 58.