Hair Growth Calculator
Calculate how long until you reach your target length or how much your hair will grow in a given time.
Average hair growth: 1.25 cm/month. Fill any field.
Growth time (mos)
Growth length (cm)
Current and final length
Current length (cm)
Final length (cm)
Results are based on statistical averages. Trims, chemical treatments and health conditions may affect growth rate.
How Many Centimetres Does Hair Grow per Month on Average?
Human hair grows on average between 1 and 1.5 cm per month — about 12–15 cm per year. The calculator uses 1.25 cm/month as its baseline, the midpoint of this range. Growth rate varies by age, genetics, nutrition and hair care habits.
Factors That Affect Hair Growth
- Genetics — the most decisive factor; determines growth rate and anagen phase length.
- Nutrition — protein, iron, zinc and biotin deficiency slows growth.
- Hormonal changes — pregnancy, thyroid disorders and menopause affect the hair cycle.
- Hair care — regular moisturising and avoiding heat damage reduce breakage.
- Season — growth may slightly accelerate in summer months.
Tips to Help Hair Grow Faster
While exceeding your genetic ceiling is not possible, the right habits can maximise your growth potential. A protein- and iron-rich diet, regular scalp massage (to boost circulation), reducing heat styling, and using a conditioner are among the most effective practices. Stress management and adequate sleep also positively influence the hair cycle.
Key Factors That Affect Hair Growth
Although hair grows an average of 1-1.5 cm per month, this rate varies significantly depending on genetics, age, nutritional habits and hair care routines. Deficiencies in protein, biotin, zinc and iron can trigger hair loss and slower growth. Regular hair care reduces split-end breakage and helps maintain total hair length over the long term.
Hair Growth Phases and Growth Rate
Hair growth consists of three main phases. In the anagen (growth) phase, hair actively grows for 2-6 years; this is the most important period determining total hair length. The catagen (transition) phase lasts 2-3 weeks, during which the hair follicle shrinks. In the telogen (resting) phase, hair prepares to shed and lasts approximately 3 months.
Effect of Nutrition and Vitamin Supplementation on Hair Growth
Deficiencies in biotin, iron, zinc and vitamin D directly affect hair growth rate. Daily protein intake is critical for hair health, as hair is largely composed of keratin protein. During periods of inadequate nutrition or rapid weight loss, hair shedding may increase and growth rate may decrease. A balanced diet and supplementation based on blood tests when necessary are therefore recommended.
Hair Care Routine: Practices That Support Growth
Regular scalp massage improves blood circulation and enhances follicle nourishment. Heat treatments and chemical applications should be minimised, and ends should be regularly trimmed to prevent breakage and split ends. Avoiding combing wet hair, braiding or tying hair at night, and reducing breakage during sleep all contribute to hair growth over the long term.