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Hair measurement, explained
Eleven guides about measuring a hairline honestly — what the numbers mean, how to take a photograph worth measuring, and where every one of these methods stops.
Crown is a measurement tool, so these guides are about measurement. Not about what to do, not about what to buy — about what a number from a photograph can honestly tell you, how to take a photograph worth measuring, and where each of these methods stops working.
Everything here is written to be useful whether or not you ever install anything. Where Crown does something specific, it says so and explains the reasoning; where a limit applies to any product in this category including ours, it says that too.
Start here
Understanding the measurements
- The Norwood scale, and what it can't tell youWhat the seven stages are, who devised them and when, and the four things a stage number leaves out.
- Hairline, temples, crown: why one number hides threeThe three zones move independently. What it means when they disagree, and which disagreements are photo artifacts.
- What hair density actually meansDensity, calibre and coverage are three different things. A photograph can only estimate one of them.
Taking the photographs
- How to photograph your own hairlineThe five variables to hold fixed so that two photos taken months apart are actually comparable.
- How to photograph your own crownFour ways to get a repeatable top-down shot of the back of your own head, alone.
- How to tell a usable hair photo from a bad oneA fifteen-second checklist, plus the failure an automatic check can never catch.
Reading the results
- Why the same head scores differently in two photosSeven causes of variance, ranked. Your actual hair is seventh, and that is the point.
- What a five-year projection is, and is notIt is arithmetic on a photograph, not a forecast about you. How to read the gap rather than the endpoint.
- Reading your own scan without spirallingThe order to read a result in, why one scan is a point and not a line, and what a number can't settle.
Choosing a tool
What you will not find here
Deliberately absent
- Anything resembling medical advice. Crown is not a medical device. These pages do not identify conditions and do not tell you what to do about what you measure.
- Product recommendations. No medication, supplement, device, clinic or procedure is named, ranked, sold or linked. Crown takes no affiliate or referral revenue from any of them.
- Invented numbers. No statistic, study or outcome appears on these pages without a link to where it came from. Where the honest answer is "no one has measured that", the page says so.
- Before-and-after photographs. Crown has no user outcome data and will not illustrate one.
First scan free. No account, no email, no login. Crown+ is $4.99/week or $39.99/year, each with a 3-day free trial.
Crown measures how hair looks in a photograph. It is not a medical device, it gives no medical advice, and nothing on this page is a substitute for a qualified professional. If something about your hair or scalp worries you, talk to one.