Hair Growth Calculator: Estimating the Time to Your Desired Length

Welcome to our Hair Growth Calculator, a practical tool designed to help you estimate the time needed to reach your hair growth goals.

Hair Growth Calculator

Hair Growth Calculator


Have you ever looked at someone’s wavy curls and wished your hair would grow this long? Or maybe you’re just wondering how your hair grows? You’re not alone! Let’s dive into the technical details behind hair growth and find out how it all works.

Hair Growth Formula

Our Hair Growth Calculator has a simple formula:

Estimated Time = (Desired Length – Current Length) / Growth Rate

However, determining the growth rate can be tricky, as studies mention the declining growth rates by age. That is why we factor in your age. Growth rates vary with respect to age as follows:

  • Under 20 – 1.25 cm (or 0.5 inches) per month,
  • From 20 to 40 – 1 cm (0.4 inches) per month,
  • 40+ – 0.75 cm (0.3 inches) per month.

The Science behind Hair Growth

Let’s uncover the intriguing science behind your hair’s growth journey from a fresh perspective.

While your hair seems to be growing calmly from the outside, a magnificent mechanism is working under your skin. It all starts with tiny hair follicles embedded in your skin. These follicles are like miniature factories and they work meticulously to produce each strand of hair.

  • Anagen Phase (Growth Phase): While you may not notice anything outside, inside your scalp is where the magic begins. At this stage, your hair follicles are overflowing with activity. The cells inside the follicles divide rapidly. As a result, new hair cells are produced. These cells are filled with a protein: Keratin. Keratin is the building block of your hair. When these cells that are rich in keratin multiply, they are pushed upwards, form the hair shaft and emerge from your scalp.
  • Catagen Phase (Transition Phase): Think of this phase as a quick pause for your hair. Your follicles shrink and separate from the blood vessels that supply them with nutrients. At this stage, your hair stops growing and prepares for its next journey.
  • Telogen Stage (Resting Phase): At this stage, your hair follicles are in a state of relaxation. Your hair does not grow actively, but it does not fall out either. This peaceful interlude may take several weeks, or even months, until your hair begins to naturally grow back.

Factors affecting Hair Growth

  1. The Role of Blood Flow
    • An important aspect of hair growth is blood flow. Oxygen and nutrients are supplied to the hair follicles by blood vessels. Hair follicles’ growth is accelerated by this means. For this reason, never forget that in addition to a healthy and balanced diet, a good blood circulation rate can also have a positive effect on your hair’s growth rate.
  2. Hormones on the Hair Growth
    • Hormones also play a vital role in hair growth. Androgens, that is a group of hormones that also includes testosterone, can affect the size and activity of hair follicles. This is why you may notice changes in your hair growth in different periods. For instance, hormone levels fluctuate during puberty, pregnancy or menopause and hair follicles are greatly affected by these fluctuations.
  3. Genetics and Hair Growth
    • It is mistakeably apparent that your genes play a crucial role for the growth potential of your hair. Some of us are genetically predisposed to have longer or thicker hair, while others have a predetermined limitation on their hair length. If you want to get the most accurate information for your hair growth potential, perhaps you should have a look at your parents or examine your family’s hair history.

Hair Fun Facts and Trivia

After the technical details, let’s spice up this place with some fun information.

  • Lifetime Hair Growth: Did you know that a person will grow an average of 590 miles (or 948 kilometers) of hair in their lifetime? This is the equivalent of commuting from New York City to Chicago; only with your hair!
  • Hair Color Wonders: Redheads have an average of around 90,000 strands, while brunettes usually have around 140,000 and blondes around 110,000. Despite these differences, hair thickness varies from person to person rather than hair color.
  • Hair as a Record Keeper: Your hair can be a living record of your life. It can carry traces of drugs, environmental pollutants, and even some of your dietary habits.

Frequently Asked Questions

Can I make my hair grow faster?

While you can’t make your hair grow overnight, you can encourage healthy growth by eating a balanced diet rich in vitamins and minerals like biotin and zinc. Gentle hair care practices, avoiding heat damage, and regular trims to prevent split ends can also help.

How accurate is the Hair Growth Calculator?

While the calculator provides a general estimate based on known averages and your input, individual experiences may vary due to numerous factors such as diet, stress, and genetics.

Does cutting my hair frequently make it grow faster?

This is a myth. Cutting your hair removes split ends and makes your hair look healthier, but it doesn’t affect the rate at which it grows.

Can I use the Hair Growth Calculator for facial and body hair?

The calculator is calibrated for scalp hair, which has a different growth rate compared to facial and body hair. Thus, it may not be accurate for those types.

Is it possible for hair to stop growing?

Hair never completely stops growing. However, it should not be forgotten that there are factors that can significantly slow down the growth rate. As mentioned in our blog, many different parameters such as age, health conditions, hormonal imbalances can be given as examples.


Hair Growth Calculator is a simple helpful guide to understand your hair growth pattern. Although it is not a hundred percent accurate tool, it provides valuable information based on some biological principles. We hope this guide and calculator will help you take correct steps on your hair growth journey.

Thanks for reading, here is your journey to achieving the ideal hair length!