Methodology
How Crown scores a hairline
Most scanning apps will not tell you how they arrived at your number. This page is Crown's, in full: the bands, the gate, the metrics, and the things Crown refuses to output.
Two photos, and what each one is for
A Crown scan is two guided photos, not one. They are not interchangeable and neither can stand in for the other.
Hairline. Front-facing, forehead fully visible. This is the only shot the hairline and the temples are read from.
Crown. Taken from above and behind, looking down at the top-back of the head. The crown is scored from this shot and effectively only this shot — a crown seen from the front is not a crown reading, and Crown will say so rather than infer one.
The score bands
Scores are not produced freehand. Every numeric reading is anchored to one of six fixed bands, so that the same photograph lands in the same place on a repeat run rather than drifting. Within a band the score is placed low, mid or high according to how the photo compares to that band's description.
| Band | What it describes |
|---|---|
| 90–100 | A dense line with no scalp visible at the part or the crown. |
| 70–89 | A matured hairline or mild rounding at the temples, with the crown still fully covered. |
| 50–69 | Clear temple recession or visible crown scalp under normal light — but not both, and the front border still holds. |
| 30–49 | A deep M-shape, a receded front with sparse strands across it, or a thinning patch at the crown. Obvious at a glance. |
| 20–29 | The front and the crown have started to meet. |
| 0–19 | A horseshoe pattern, or near-total loss across the top. |
A shaved or fully bald scalp is still scoreable. If the scalp itself is clearly visible it gets a number in the lowest band — it does not return a blank. A blank means Crown could not see the zone, never there was nothing there. That distinction is the whole design.
The rule that produces a blank
Before any zone is scored, Crown estimates how clearly that zone is actually exposed in the best available image. A zone is scored only if it clears that visibility bar. Below it, the score is null and Crown reports why instead of estimating.
This is the single most important thing to understand about the output. An app that always returns a number for every zone is not gating on evidence — it is filling in. Crown would rather hand you a blank and the angle that would fix it.
| Reason | What Crown tells you |
|---|---|
| Covered by hair | Retake with it pulled back. |
| Headwear | Retake bare-headed. |
| Wrong angle | Retake aiming straight at this zone. |
| Blur or darkness | Hold steady and retake. |
| Not pictured | Add the angle that shows it. |
Two further gates run on the phone, before a photo is ever uploaded: one rejects a frame that is too dark to read, and one rejects a frame with no head in it. Those two catch the obvious failures at no cost and without sending anything anywhere.
The Hair Score
The overall Hair Score, 0–100, is the read across the zones that were actually scored — not across all three regardless. If only the hairline and temples were readable, the Hair Score describes the hairline and temples. If no zone was readable, there is no Hair Score, and Crown says that rather than producing one anyway.
This is why the overall number should be the last thing you read, not the first. It is a summary of a set whose membership changes between scans.
The three zones
The front border. Read from the hairline shot. Returns a blank if hair or a fringe covers it.
The two corners where the front border meets the sides. May be read from the hairline shot.
The whorl at the top-back. Read only from a top or back view. If you did not take that shot, this zone is blank — it is never estimated from the front.
The seven appearance metrics
Beside the zone scores, Crown reports seven metrics. They describe appearance — how the hair looks in the photograph — and they sit next to the zone reading rather than changing it. Each one has an angle it requires, and each one goes blank when that angle is missing or when Crown's own certainty for it is too low.
| Metric | Reports | Needs |
|---|---|---|
| Density | 0–100 | Any shot |
| Hairline stage | 1–6 | The hairline shot |
| Strand caliber | Fine / medium / coarse | A close hairline or crown shot |
| Shine | 0–100 | Any shot |
| Pigment | A greying range, e.g. 10–30% | Any shot |
| Coverage | 0–100 | The crown shot |
| Show-through | 0–100 | The crown shot |
Two of those deserve a note. Density is labelled an impression on purpose — a photograph cannot count follicles, and what density actually means is worth ten minutes of your time. Show-through is how much scalp is visible in the frame. It is a fullness cue, not a statement about your scalp.
Note that Coverage and Show-through both require the crown shot. Skip that photo and two of your seven metrics go blank. That is the most common reason a scan comes back thinner than expected.
Confidence
Every scan carries a confidence of low, medium or high. Low means the read was limited by lighting or angle. A low-confidence scan is not a bad result — it is a result that is telling you to fix the photo before you draw a line through it.
The five-year outlook
Crown returns three numbers, not one: the score now, a path where nothing changes, and a path with consistent care. The no-change path is never higher than today's score. The full reasoning — and why the gap between the two paths is the informative part — is on the projection page.
What Crown deliberately does not return
Not in the output, by design
- Any medical determination. Crown does not name, identify or rule out a condition. It is not a medical device.
- Any product recommendation. Crown does not suggest, evaluate, sell or link to a medication, supplement, device, clinic or procedure, and earns nothing from any of them.
- A number for a zone it could not see. Ever.
- A ranking against other people. There is no leaderboard and no percentile. Your only useful comparison is your own last scan.
- A promise. The five-year figures are illustrations, not commitments.
The honest limit on repeatability
The band system exists so that one photograph scores the same way twice. It does nothing at all about two different photographs. Change the light, the tilt of your chin, or whether your hair is dry, and you have taken a different measurement — one that is correctly reporting a different image.
Holding a repeat read of the same image within a few points is the target the rubric is written against. It is a design target, not a published measurement, and we would rather say so than imply a precision we have not demonstrated. Everything useful about tracking depends on you controlling the photo, which is what the capture guides are for.
Common questions
How many photos does a Crown scan need?
Two: a front-facing hairline shot and a top-down crown shot. You can submit only one, but the zones and metrics that need the missing angle will come back blank rather than estimated.
Why did one of my zones have no score?
Because Crown could not see it clearly enough. A zone is scored only when it clears a visibility bar; below that, Crown reports the reason — covered by hair, headwear, wrong angle, blur, or not pictured — and the angle that would fix it, instead of estimating a number.
Does Crown score my crown from the front photo?
No. The crown is read only from a top or back view. If you did not take that shot, the crown zone is blank.
Is the Hair Score an average of the three zones?
It is a read across the zones that were actually scored, not across all three regardless. If only two zones were readable, the Hair Score describes those two.
Does Crown diagnose hair loss?
No. Crown is not a medical device and gives no medical advice. It reports how hair appears in a photograph. If something about your hair or scalp worries you, that is a conversation for a qualified professional.
Keep reading
- Hairline, temples, crown: why one number hides threeThe three zones move independently. What it means when they disagree, and which disagreements are photo artifacts.
- 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.
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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.