The average is a half inch per month.
It depends .... How much are you willing to pay for extensions( Indian hair)? And do you mind having a bumby scalp ? Long real hair can be yours for under $500 .... Or like others have stated ... Half inch a month.
The little bit of hair on my head grows about 1/2 inch per month. The hair in my nose and ears grows about 3 inches per month.
The average rate is 1.25 centimetres per month .