The average hair growth rate is half an inch/ month. Some people grow more, some less. I grow about half an inch a month/ rather by the 6 weeks when I measure ( yes, im that sad ..
erplexed). sometimes less, sometimes more. My main problem is retention. As I have colour in my hair, im maintaining my length and cutting my clolour off as it grows 'cos my hair didn't like it. I grow more when im co-washing most days.
Mixed race or people of other races can afford to wash their hair everyday/everyother day without thinking too much about it and this definitely aids growth. They also don't have much of a problem with retention hence they seem to 'grow' hair easier. We all grow at a similar pace, however, we (black women) have issues with maintenance and retention unfortunately
As the other ladies have said, not enough information about best way to go about it .... yet.