How Many Hairs Grow On The Human Head?

The average number of hairs on a healthy person’s head is 100,000. This number can vary in the range of 80,000 to 150,000 from person to person.

You will be surprised to know that the number of hairs also varies with the person’s hair color. According to Professor Dr. Rainer Flindt, the author of a famous book called “Amazing Numbers in Biology”, the blonde hair person has typically more number of hairs as compared to red hair person.

Head Hair colorNumber of hairs
Blonde150,000
Brown-haired110,000
Black-haired100,000
Red-haired90,000
Source

It is found that on average a typical person has 100,000 hair follicles which are small pouches in our head scalp through which hair grows and responsible for hair growths. According to the American Academy of Dermatology Association (AAD), a human body has about 5 million hair follicles distributed over the whole human body except on the hand palms, feet soles, and red lips.

As per one research on “distribution of human hair in follicular units”, the number of follicle units per square centimeter ranges between 65 and 85 while the hair density on a human head ranges from 124 to 200. The distribution of hairs also varies with the part of the head. For example, the hair density (number of hairs per centimeter square) at the part in the hair is about 300-320, while the hair density at the back of the head and forehead is 200-240.

As per the Genetic Home Reference study, 90% of the world’s population has black and brown colored hairs due to the presence of a high amount of a dark pigment called eumelanin. Therefore, on average a human has 100,000 hairs on their head scalp which matches the number of hair follicles on the head.

Here are some interesting facts about human hairs.

  • The human head hair grows at a rate of 0.35 mm per day that is 0.41 inches per month and 5 inches in a year.
  • On average, the diameter of adult human male head hair is about 0.071 mm.
  • The Hair color is determined by the amount of a pigment called melanin. The gene responsible for the human hair color is MC1R.
  • We daily lose about 50 to 100 hairs from our head scalp.
  • Human hairs grow faster in warm weather as compared to cold weather because warm conditions stimulate the growth of the hair.
  • Wet hair has 30% more elastic strength as compared to dry hair.

Professor Atom

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Professor Atom is a science enthusiast and alumni of IIT Bombay. According to him, every question can be solved with curiosity and mind mapping. ( Curiosity = Asking Questions = Learning )

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