A: The speed of hair growth is roughly 1.25 centimeters or 0.5 inches per
month, being about 15 centimeters or 6 inches per year.
With age the speed of hairgrowth 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.
Hair grows at about the same speed all over your
head. There is no perceptible difference between the
fringe, nape, crown, ...
You might think that fringes (bangs) grow faster
than hair on other parts of your head, but that's
simply an illusion. Many cut the fringe just above the eyebrows and
because of this the slightest hairgrowth 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.