Enter your current hair length, target length, gender, ethnicity, and age into the Hair Growth Calculator to estimate how long it will take to reach your goal. Adjust for your growth rate, regular trims, and breakage to get a personalized timeline. You'll see your estimated months to goal, projected final length, and a month-by-month growth schedule.
Estimated Months to Goal
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Adjusted Growth Rate
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Length to Grow
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Approx. Years & Months
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Base Growth Rate
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On average, hair grows about 1.25 cm (half an inch) per month, or roughly 15 cm (6 inches) per year. However, this varies by genetics, ethnicity, age, gender, and overall health. Asian hair tends to grow fastest, followed by Caucasian, then African hair types.
Research shows that hair growth rates differ by ethnicity. Asian hair tends to grow fastest (around 1.3–1.4 cm/month), Caucasian hair grows at an average rate (~1.2 cm/month), and African hair typically grows slower (~0.9 cm/month). The calculator applies these factors to personalize your estimate.
Yes. Hair growth is generally fastest in your 20s and 30s, then gradually slows as you age. After 50, hair follicles become less active and some may stop producing hair altogether. The calculator adjusts the base growth rate based on the age group you fall into.
Hormones play a major role. Estrogen (higher in women) can prolong the active growth phase (anagen) of the hair cycle, while testosterone (higher in men) can shorten it. This means women often experience slightly longer continuous hair growth phases than men.
Breakage reduces the net length your hair gains each month. For example, if you have 25% breakage, only 75% of your monthly growth actually contributes to length retention. Managing breakage through proper conditioning, avoiding heat damage, and gentle handling can significantly speed up your visible progress.
Trimming does not make hair grow faster — growth happens at the scalp. However, regular trims remove split ends and prevent breakage from traveling up the hair shaft, which can actually help retain length over time. The calculator lets you account for trim frequency so you can see the net effect on your timeline.
Hair grows in three main phases: Anagen (the active growth phase, lasting 2–7 years), Catagen (a short transitional phase of 2–3 weeks), and Telogen (the resting/shedding phase, lasting about 3 months). At any time, most of your hairs are in the anagen phase.
Key factors include genetics, age, gender, ethnicity, diet and nutrition (especially protein, iron, and biotin), hormone levels, scalp health, stress, and underlying medical conditions. While you can't change your genetics, maintaining a healthy lifestyle and minimizing breakage will help you reach your length goals sooner.