Get personalized hair growth predictions and recommendations based on your unique characteristics.
Calculate NowPersonalised insights factoring in trims, damage, seasonality, and your event goals.
Predict how long your hair will be after a chosen timeframe.
Start by providing your age and gender. These factors significantly influence hair growth rates and help us provide more accurate calculations.
Select your current hair loss stage and indicate if you have a family history of hair loss. This information helps us determine potential genetic factors affecting your hair growth.
After clicking calculate, you'll receive personalized information about your expected monthly and yearly hair growth rates, along with tailored recommendations for your situation.
Note: This calculator provides estimates based on average growth rates and common factors affecting hair growth. Individual results may vary, and it's always recommended to consult with a healthcare professional for personalized advice.
Hair growth occurs in three main phases:
Genetics play a crucial role in determining hair growth patterns, thickness, and potential for hair loss. Understanding your family history can help predict future patterns.
Hormones, especially DHT (dihydrotestosterone), significantly impact hair growth and loss patterns in both men and women.
If you're experiencing significant hair loss or concerned about your hair growth rate, consider consulting a dermatologist or trichologist. They can provide personalized treatment plans and professional advice based on your specific situation.
The hair growth rate calculation starts from a simple baseline: scalp hair grows about 0.5 inches (1.25 cm) per month for most people, around 6 inches (15 cm) per year. The calculator then adjusts that baseline using factors with a known influence on growth - age, hair type, diet quality, stress, damage from heat or colour, and how often you trim.
The core formula is: projected length = current length + (adjusted monthly rate x months) - trim reduction. Because each multiplier is an average, think of the output as a realistic estimate of your range, not a guarantee.
To estimate time instead of length, the calculation flips: months needed = (goal length - current length) / monthly growth rate. Going from shoulder-length (about 12 in / 30 cm) to waist-length (about 30 in / 76 cm) means growing 18 inches - roughly 3 years at the average rate before trims.
The "Reach Goal Length" mode above runs this hair growth time calculation with your personal factors, and the "Event Deadline" mode checks whether a wedding or photoshoot date is realistic for your target.
This hair growth chart shows the typical length increase at the average growth rate. Use it as a quick reference, then run the calculator for numbers adjusted to you.
| Timeframe | Typical length increase | In centimetres |
|---|---|---|
| 3 months | about 1.5 in | about 3.8 cm |
| 6 months | about 3 in | about 7.6 cm |
| 12 months | about 6 in | about 15 cm |
| 18 months | about 9 in | about 23 cm |
| 24 months | about 12 in | about 30 cm |
Real hair length increase depends on your anagen (growth) phase, which genetics cap at roughly 2-7 years - that is why maximum achievable length differs so much between people.
Women searching for a hair growth calculator usually want the same answer with different inputs. Baseline growth speed is broadly similar across genders, but hormonal shifts - pregnancy, postpartum shedding, menopause - can temporarily change how much hair is in its growth phase. Colouring, heat styling, and tight protective styles also shape the visible result.
The calculator's gender, age, and damage inputs account for these averages. For sudden or significant changes in shedding, a dermatologist is the right next step - hormonal and medical causes need a professional eye, not an estimator.
On average, hair grows about half an inch (1.25 cm) per month, or roughly 6 inches (15 cm) per year. Your age, genetics, hair type, and overall health move that number up or down, which is what this calculator estimates.
At the average rate of about half an inch per month, growing 12 inches takes roughly 24 months. Frequent trims, heat damage, and breakage stretch that timeline, so the personalised estimate from the calculator is usually more realistic than the simple average.
It is an estimator, not a diagnosis. The calculation starts from average growth rates and adjusts them with well-documented factors like age, hair type, trim cadence, and damage. Treat the result as a planning guide - real-world results vary from person to person.
Growth speed is broadly similar across genders, with small average differences. Hormonal changes such as pregnancy or menopause, plus styling and colouring habits, often matter more for women than the baseline rate itself.
If you notice sustained shedding, visible thinning, patchiness, or scalp irritation, consult a dermatologist or trichologist. This calculator is informational and cannot evaluate medical causes of hair loss.
Disclaimer: Everything on this page is informational. Growth estimates are based on population averages and your results will vary. For hair-loss concerns, diagnosis, or treatment, consult a dermatologist.
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