Hair Growth Calculator
Customize your growth rate, trim schedule, and length target to map a realistic timeline for your next milestone.
Measure from scalp to the ends.
Typical growth is ~0.5 inches/month.
Half-inch trims every few months maintain healthy ends.
Growth Timeline
Length to grow
10 in
Months needed
24.4
Estimated target date
December 2027
How to Use This Calculator
Measure accurately
Use a flexible tape along strands from scalp to the longest point. Record your baseline for future check-ins.
Know your growth rate
Hair grows ~0.3–0.6 inches/month. Track your own by measuring every 4 weeks and updating the calculator.
Factor in trims
Healthy trims maintain ends but slow progress. Input interval and amount to get a realistic timeline.
Formula
Net Growth = Monthly Growth − (Trim Amount × 4.345 ÷ Trim Weeks)
Months Needed = (Goal − Current) ÷ Net Growth
Target Date = Today + Months Needed
Example: Grow 10 in, monthly growth 0.5 in, trims 0.25 in every 12 weeks → Net growth ≈ 0.41 in/month → 24.4 months to goal.
Healthy Growth Tips
Consistency beats quick fixes. Combine nutrition, gentle styling, and protective habits to maximize each growth cycle.
- Keep scalp clean and stimulated with massage to support follicles.
- Use satin/silk pillowcases or bonnets to reduce breakage while sleeping.
- Limit heat tools and chemical services that compromise length retention.
- Balance protein and moisture treatments based on hair porosity.
Frequently Asked Questions
How accurate is the growth rate?
It’s an average. Health, genetics, and care routines influence speed. Recalculate as you observe progress for better precision.
Should I include breakage?
Breakage effectively reduces growth. If you experience frequent breakage, lower the monthly growth input until trims plus breakage match what you retain.
Can I plan for multiple length goals?
Yes—duplicate your inputs with different goal lengths (shoulder, bra-strap, waist) to forecast each milestone.
Does trimming slow growth?
Trimming doesn’t affect follicles but removes length. The calculator shows how maintenance affects the net growth you keep.