How much hair and nail will you grow?
Hair grows about a centimetre a month, which sounds trivial until you multiply it by a hundred thousand follicles and seventy years.
91% of a beard hair
10 mm is faster than 3 of the 5 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| toenails | 1.6 mm | 6.25× | |
| fingernails | 3.5 mm | 2.86× | About 3.5 mm a month |
| eyelashes | 5 mm | 2× | |
| beard hair | 11 mm | 0.909× | |
| head hair | 12.5 mm | 0.8× | About 1.25 cm a month |
Worth knowing
- Head hair grows about 15 cm a year, so hair reaching the waist represents six or seven years of uninterrupted growth.
- Add up all 100 000 follicles and an adult grows about 15 km of hair a year in total length.
Frequently asked
How fast does hair grow?
About 1.25 cm a month, or 15 cm a year, though this varies by 30% between individuals and slows with age.
Why does hair stop at a certain length?
Because each follicle cycles: two to seven years of growth, then rest, then shedding. The length you can reach is set by how long your growth phase lasts.