On average, human hair grows about 1 to 1.5 centimeters (approximately 0.4 to 0.6 inches) per month. This corresponds to roughly half an inch per month or about 6 inches (15 cm) per year, although individual rates can vary significantly
Factors influencing hair growth rate:
- Genetics and ethnicity: For example, Asian hair tends to grow faster (up to 1.25 cm or more per month) than Caucasian or African hair, which may grow slower (around 0.5 to 0.8 cm per month)
- Age: Hair growth tends to slow down with age.
- Sex: Some studies suggest women's hair may grow slightly faster than men's, but differences are small
- Health and hormones: Conditions like pregnancy or hormonal imbalances can affect growth rates.
- Hair care and breakage: Proper care can maximize retained length by preventing breakage
Hair growth cycle:
Hair grows primarily during the anagen (growth) phase, lasting 2-6 years, at about 1.3 cm per month on average. This is followed by shorter catagen (transition) and telogen (resting/shedding) phases, during which growth slows or stops
Summary:
- Typical monthly hair growth: 0.5 to 1.7 cm (0.2 to 0.7 inches)
- Average often cited: about 1.3 cm (0.5 inch) per month
- Annual growth: 6 to 20 cm (2.4 to 8 inches), depending on individual factors
Thus, while the commonly accepted average is about half an inch per month, actual growth can vary from person to person based on genetics, ethnicity, age, and health
