Incredible Can All Hair Grow Long Ideas. The american academy of dermatology reports that hair grows an average of around half an inch each month, which amounts to six inches over the year. With a little care, however, you can encourage your hair to grow longer.

Web on average, hair tends to grow between 0.5 and 1.7 centimeters per month. At least if you want it to look decently kempt. With a little care, however, you can encourage your hair to grow longer.