Hair Growth Calculator
Calculate hair growth length over time, time needed for target length, and predict future hair length
Hair Growth Calculator
Growth rate: 0.5" per month
How long to track hair growth
Hair Growth Results
Hair Growth Rate Comparison
Example Calculation
Scalp Hair Growth Example
Question: How long will my hair grow in 1 year?
Hair Type: Scalp hair
Time Period: 1 year = 12 months
Growth Rate: 0.5 inches per month
Calculation
Hair Growth = Growth Rate × Time
Hair Growth = 0.5 inches/month × 12 months
Hair Growth = 6 inches (15.2 cm)
Real-World Context
• Average person loses 50-100 hairs per day
• Hair growth can vary ±20% from average rates
• Factors: genetics, age, nutrition, health, hormones
• Growth may slow with age or during stress
Hair Growth Cycle
Anagen Phase
2-6 years for scalp
Active growth phase
Catagen Phase
About 2 weeks
Transitional phase
Telogen Phase
About 100 days
Resting phase
Factors Affecting Growth
Genetics
Primary determinant of growth rate
Age
Peak growth between 15-30 years
Nutrition
Protein, vitamins, and minerals
Hormones
Thyroid, testosterone, estrogen
Health & Stress
Can slow or accelerate cycle
Hair Growth Tips
Eat protein-rich foods for hair structure
Stay hydrated for healthy follicles
Massage scalp to improve circulation
Protect from excessive heat and chemicals
Get adequate sleep for hormone regulation
Understanding Hair Growth
How Hair Grows
Hair growth occurs in cycles consisting of three phases: anagen (growth), catagen (transition), and telogen (rest). During the anagen phase, hair follicles actively produce new hair cells, pushing existing hair up and out of the scalp.
Growth Rates by Hair Type
- •Scalp hair: 0.5 inches per month (6 inches per year)
- •Facial hair: 0.6 inches per month (fastest growing)
- •Body hair: 0.25 inches per month
- •Eyebrows: 0.16 inches per month
- •Eyelashes: 0.12 inches per month (slowest)
Calculation Formula
Hair Length = Growth Rate × Time
L = R × t
- L: Hair length grown (inches)
- R: Growth rate (inches per month)
- t: Time period (months)
Note: Individual growth rates can vary ±20% from average values due to genetics, health, age, and environmental factors.
Frequently Asked Questions
Does cutting hair make it grow faster?
No, cutting hair doesn't affect the growth rate from the follicle. However, regular trims can prevent split ends from traveling up the hair shaft, reducing breakage.
Why does hair stop growing at a certain length?
Hair appears to stop growing because it reaches its genetically predetermined maximum length during the anagen phase, then falls out during the telogen phase.
Can you speed up hair growth?
While you can't dramatically change your genetic growth rate, proper nutrition, scalp massage, avoiding damage, and managing stress can optimize your natural growth potential.
How much hair do we lose daily?
It's normal to lose 50-100 hairs per day. Since we have about 100,000 hair follicles on our scalp, this loss is typically not noticeable.