How Fast Does Hair Grow?

So you decided to try a new hairstyle and guess what? You hate it. What were you thinking? Probably not what you're thinking now and that's "how fast will your hair grow back?"

The good news is your hair is already growing, and probably quicker than you think. But you won't wake up tomorrow looking like Rapunzel. That would take a while. So just how fast does hair grow and what affects it? Let's start by explaining the parts of your hair.

How Hair Is Structured

A single hair has several parts, including a hair shaft and a hair root. The shaft is the strand of hair you see sticking out of your skin. The root goes deep down into layers of your skin, and is surrounded by the hair follicle.

All of your hair follicles are attached to muscles that can make the hairs stand up. Then at the base of the hair is the bulb. The bulb is where new hair cells are produced.

Phases of Hair Growth

Now that you know the structure of your hair, let's talk about the phases it goes through when it's growing. Every hair grows in three phases. During each phase your hair is growing or resting; for how long depends on factors we'll discuss next.

Cell generation occurs during the anagen phase, which means about 90 percent of your hair grows during this time. How long the anagen phase lasts depends on where the hair is on your body. For instance, the anagen phase for hair on your scalp can last for two to six years, but it's much shorter for other body hair, like your eyelashes and eyebrows.

During the yearslong anagen phase, the hair on your scalp can grow a third of an inch (1 centimeter) every 28 or so days — that would be about 5 inches (13 centimeters) a year. But how fast it really grows depends on things like your age, genetics, type of hair and overall health. A 2016 study published in the European Journal of Dermatology found that Asian hair grows the fastest, while African hair grows the slowest.

Regardless of how fast your hair grows, just remember, it will grow back. Even after a bad haircut.