Why do we have to keep getting haircuts? Because our hair grows every minute of our lives, as do our nails. So which grows faster? Hair grows about 1/2 inch each month, but it's a little different for everyone. If you measure your hair today and wait a couple of months for a haircut, you can find out your own hair speed! Meanwhile, fingernails grow about 1/8 of an inch each month. The longer the finger bone, the faster that nail grows, so your pinky nail is the slowest. Your toenails grow only 1/4 as fast as your fingernails -- good thing, because they're harder to reach!