Hair Growth Calculator — Plan Your Length Goal

Your next hair goal.
A little more clear.

Estimate your future length, plan a grow-out, or see where you could be by a special date.

Small growth.
Long-term plans.

Free to use. No signup.
Your measurements stay in your browser.

INCHES + CENTIMETERSTRIM-AWARE ESTIMATESYOUR OWN GROWTH RATE

Build your growth plan

01 / YOUR INPUTS

What would you like to know?

Measurement unitsInchesCentimeters

Current length in Goal length in

Measure from the same scalp point to the ends each time. Use gently stretched length for curls.

Start date

Growth rate

The starting assumption is about 0.39 in (1 cm) per month. Your actual rate can differ.

Include planned trims Optional

Amount per trim inTrim every months

First trim happens one full interval after your start date. Use 0 for no trims.

Your growth outlook

02 / THE PROJECTION

ESTIMATED TIME TO YOUR GOAL

—

Starting length—

Goal length—

Growth rate—

Your length over time

Planned length

A different pace changes the plan

These are “what if” scenarios at 20% lower and up to 20% higher growth rates, not a medical confidence range.

A planning estimate, not a promise. Individual growth, shedding and breakage vary. This tool does not diagnose hair loss or predict treatment results.

Your milestones

03 / MONTH BY MONTH

Hair length projections after scheduled trims
Time	Approx. date	Projected length	Length trimmed

Dates use an average month of 30.44 days. A trim due at a milestone is included in that row.

UNDERSTAND YOUR ESTIMATE

How the hair growth
calculator works

Start with a length and monthly growth rate. The planner adds growth as time passes and subtracts each scheduled trim. It shows the first estimated time you reach your goal, or your projected length at a chosen date.

Future length = current length + growth − scheduled trims

For example, at 1 cm per month, 20 cm becomes 26 cm after six months without trims. Two 0.5 cm trims during that period leave 25 cm.

For measured rates, the formula is (current length − earlier length + past trims) ÷ elapsed months. It is a length-retention estimate; it cannot separate unmeasured breakage from growth.

Scalp hair grows in cycles. Long projections are increasingly uncertain, so this tool caps plans at 10 years and does not model a biological maximum hair length.

A FEW GOOD QUESTIONS

Before you grow

How fast does hair grow in a month?

DermNet describes hair shaft growth at about 1 cm per month. This calculator uses that as a starting assumption. Rates vary, so your consistently recorded measurements can make the plan more relevant to you.

Do trims make hair grow faster?

Trimming removes length at the ends; it does not increase the growth rate used here. The calculator subtracts trims separately so you can see their effect on your length goal.

Can I use this for curly or coily hair?

Yes. Measure a section gently stretched each time, from the same scalp point. The result estimates that measured length, not how far your curls hang when dry. Switching between stretched and unstretched measurements makes the estimate less useful.

What if my goal is never reached?

Your trims may offset growth, or your goal may take more than the 10-year planning limit. Review the inputs. A calculator cannot assess the biological reason your hair appears to stop growing.

Is my information stored?

Calculations run in your browser. The calculator saves only when you choose “Save on this device,” using that browser’s local storage. Delete it with “Delete saved plan.” Downloads stay on your device. The calculator itself sends no measurements to a server; the surrounding website may have its own analytics.

Can this predict hair-loss recovery?

No. This is a length planner, not a recovery or treatment calculator. If you notice sudden shedding, bald patches or scalp symptoms, seek advice from a qualified healthcare professional.