Here's exactly how long guys should go in between haircuts
If you follow that rule, you may not be going as often as you need to - or you may be going too often. That common once-a-month rule is actually much more flexible than you think.
It all depends on the length of the cut you're looking to maintain. For someone with shorter, razored hair on the sides, in order to maintain that style you will need to go back to the barbershop every two weeks, according to Riki Bryan, a strategist who works with New York City- and San Francisco-based barbershop chain Fellow Barber.
If you have a longer haircut, say an inch or two all around, a month is an acceptable amount of time to go in between cuts.
That's because hair always grows at the same rate - about 0.5 inches every four weeks, according to GQ. It's all about maintaining ratios.
Since 0.5 inches can be up to double the length of the shorter sides of a close-cropped, clippered haircut, to maintain that shape you must go within a few weeks. However, if your hair is two inches or longer, that ratio of growth after a month is going to be much smaller, and no one will really notice a 0.5-inch increase in hair length.
Basically, the longer your hair is, the longer you can go without getting it cut. However, we'd still follow a plus- or minus-two-week range from a month schedule.
After six weeks, you're going to need at least a trim, no matter how long your hair is.