Textured Hair Care
Hair length retention tracker.
Hair grows, but length is only kept if it does not break off. Enter your starting length, current length, months between and any length you trimmed, and see how much of the average growth you kept. Runs in your browser; nothing is sent or stored.
Your measurements
Your retention
Fill the form and press Calculate.
Answer in brief
Compare actual length gained with half an inch a month of average growth to see retention and breakage.
Worked example
Starting at 10 in, now 13 in after 8 months, with 0.5 in trimmed. Baseline growth is 8 x 0.5 = 4.00 in. The net change is +3.00 in, so the growth you kept is 3.00 + 0.50 = 3.50 in, which is 88% of baseline, a shortfall of 0.50 in. At baseline growth, reaching 18 in from 13 in takes 10 months.
How it works
Healthline gives average hair growth as half an inch a month, about six inches a year, and says genetics play a big role in how quickly and fully your own hair grows. Baseline growth = months x 0.5 in. Net change = current minus starting length. Growth kept = net change + length trimmed. Retention = growth kept / baseline growth. Shortfall = baseline - growth kept, which is the length lost to breakage or slower-than-average growth. Months to goal = (goal - current) / 0.5 in, assuming no breakage.
Measure the same way each time, for example stretched, from the same spot, because shrinkage makes curly and coily hair measure shorter than it is. A Baylor College of Medicine dermatologist notes that no style makes hair grow more or less, but protecting hair can help retain length by reducing breakage. Related: hair growth goal calculator.
Not professional advice. This is general cosmetic hair care information. For scalp conditions, hair loss, pain or irritation, see a board-certified dermatologist.
Sources (retrieved 2026-10-15):
- How to Grow Hair Faster for Men: Facts and Myths, Healthline
- Braids for curly and coily hair: Baylor dermatologist weighs in, Baylor College of Medicine Blog Network
FAQ
How fast does hair grow per month?
Healthline gives an average of half an inch per month, or about six inches per year, and says genetics play a big role in how quickly and fully your hair grows.
What is length retention?
The share of the length your hair grew that you actually kept, after breakage and trims. This tool compares it with the average growth baseline.
Does 100% retention mean no breakage?
Not exactly. Everyone grows at a different rate, so a result near 100% means your net length matches the average growth, and above 100% means you grow faster than average.
Why did I lose length?
Breakage is a common cause. A Baylor dermatologist says hair can break while in a style from tension, dryness or rubbing, and during takedown.
How do I measure curly or coily hair?
Measure stretched, from the same spot, each time. Curly and coily hair shrinks, so unstretched length is shorter than the real length.