How Fast Does Hair Grow?

Measuring how fast hair grows with
Measuring hair growth - Photo: Shutterstock
Q: How fast does hair grow?
A: The speed of hair growth is roughly 1.25 centimeters or 0.5 inch per month, being about 15 centimeters or 6 inches per year. With age the speed of hair growth might slow down to as little as 0.25 cm or 0.1 inch a month.
Cell division is responsible for the hair growth cycle. The new cells push the hair forward to make it longer, so the new hair is added at the root.
There are about 100.000 hairs on a healthy scalp of hair. Each of these hairs will, in normal healthy conditions, last for one up to six years. People loose about 100 hairs per day, in normal conditions. The fallen hairs are replaced by new hair. Baldness occurs when new hairs are not being produced anymore.
During it's life a hair goes through three phases of growth: the anagen, the telogen and the catagen. The anagen is the first phase with new hair growing in the hair bulb. The catagen is the following phase when hair stops growing because the cell division stopped. The telogen is the final phase. New hair starts growing in the papilla and finally the old hair falls out.
The anagen, catagen and telogen phases of hair growth
Hair growth per month - How fast hair grows
Hair grows at about the same speed all over your head. There is no perceptible difference between the bangs, nape, crown,...
You might think that bangs grow faster than hair on other parts of your head, but that's simply an illusion. Many cut the bangs just above the eyebrows and because of this the slightest hair growth will be visible.
Wearing a turtleneck will also make your hair look longer and maybe make you think that your hair grows faster. Again an illusion has been created here because of the straight line of the turtleneck.

See also:
What exactly is hair made of and how does it grow?
How can I improve my hair growth?
Is hair growth influenced by what you eat?