Hair Growth Calculator

Human hair grows everywhere on the body except for lips, soles of feet, the palm of your hands, eyelashes, eyelids and scar tissue.

First, it is important to know that losing hair is a natural part of the hair growth cycle, the cycle consists of 3 stages and they are very important to know as they can help understand and recognize problems with your hair. Also important to note that each strand of hair on the human body is at its own stage.

This hair growth calculator will calculate how much hair you will grow in a certain amount of months, using the average amount of hair grown by a person in a month, as everyone can grow hair at different speeds. The hair growth calculators purpose is to give a general estimate.

Hair Growth Formula: Months/Growth Rate

How to calculate Hair Growth

As mentioned above we use half an inch as our growth rate. Therefore to calculate how much hair is grown in 5 months: 5 /0.5 = 2.5 inches of hair grown in 5 months.

The 3 stages are

Anagen Phase

The hair growth cycle starts with Anagen which is the growth phase. It begins in the papilla, where the cells divide to produce new hair fibers and this lasts from two - six years depending on genetics. The longer a strand of hair is in this stage the longer it will grow.

Some points to keep in mind about Anagen state

  • Your hair grows around half an inch a month and faster in the summer than in the winter.
  • Lasts 2-6 years depending on genetics.
  • About 85 percent of hair on anyone's head is in the anagen phase at all times.
  • Arm hair is shorter as the anagen stage/growth phase is very short.

Catagen Phase

Catagen phase also known as the transitional phase is right after Anagen, it lasts for about 2-3 weeks in which the hair is no longer growing. Outer roots shrink and attach to the root of the hair, this is how club hairs occur. The club hair leads to the next stage of the cycle which is the shedding cycle

  • About 3 percent of all hairs are in this phase at any time.
  • Lasts about 2-3 weeks.

Telogen phase

Eventually, your hair enters the telogen phase also known as the resting phase. What happens is the follicle remains dormant for one - four months and the club hair is completely formed. At the end of this stage, hairs will begin to fall out and the whole process is repeated.

  • Usually about 10-15 percent of hairs on the head are in this phase.
  • Typically in any given day you will shed 50 - 100 hairs on a healthy head of hair.


How to Use Hair Growth Calculator


Enter the amount of months growing your hair

Press Calculate.

The length of hair grown within that time frame will be displayed in inches.

Hair Growth Calculator