How fast does hair grow?
Scalp hair grows about half an inch, or 1.25 centimeters, a month on average. That adds up to roughly six inches a year. Some people grow closer to a third of an inch a month and others nearer two thirds, depending on genetics, age, hormones and overall health. Growth is usually fastest from your teens to your thirties and slows a little after that.
Hair grows in cycles. Each strand spends two to seven years in the growing phase, then rests and sheds. The length of your growing phase sets your terminal length, the longest your hair can reach before it naturally falls out. That is why some people can grow hair to the waist and others find it stalls around the shoulders.
How the calculator works
- Growth per month. Pick slow, average or fast. If you have measured your own growth over a few months, choose the closest option.
- Trim loss. We spread each trim across the weeks between cuts. A quarter inch every 12 weeks costs you about 0.08 inches a month.
- Net growth. Growth minus trim loss is the real gain each month.
- Time to goal. The gap between your current and goal length divided by net growth gives the months, and we turn that into a target date and a timeline.
Common hair length milestones
| Length name | Approximate length | From a chin bob at average growth |
|---|---|---|
| Chin length | 8 to 10 in (20 to 25 cm) | Starting point |
| Shoulder length | 12 in (30 cm) | About 6 months |
| Armpit length | 14 in (35 cm) | About 10 months |
| Bra strap length | 16 to 18 in (40 to 45 cm) | About 1 to 1.5 years |
| Waist length | 22 to 26 in (55 to 65 cm) | About 2 to 3 years |
Tips to keep the length you grow
You can't change your natural growth speed much, but you can stop losing length to breakage. Keep heat styling to a minimum, detangle gently from the ends up, sleep on a silk or satin pillowcase and use a leave in conditioner on the lengths. Small, regular trims of an eighth to a quarter inch remove split ends before they travel up the strand, so they save length in the long run.
Looking for styles to grow into? Browse our long hairstyles guide, long layered cuts and soft waves for long hair, and use the face shape finder to pick a length that flatters you.