Chin Length Adds Height
Every extra millimetre carried at the chin stretches the face downward.
Free AI Tool — Millimetre-Precise
Beard Length Advisor
A beard length advisor is an AI tool that measures your face shape from facial landmarks, then converts that shape into trimmer settings in millimetres — how long to leave it at the chin, how short to keep it on the cheeks, and why those two numbers shouldn't match.
Most beard advice stops at a style name. This tool starts where that advice ends: upload a photo, and the numbers you get back are ready to dial into a trimmer, not just a picture to show your barber and hope they interpret it the same way you do.
Settings in
millimetres
millimetres
Never stored,
always private
always private
2 free scans
daily, no sign-up
daily, no sign-up
1 Upload Your Photo
Reading your face shape…
AI analysis in progress
2 Your Length Guide
Your face shape and the trimmer settings that suit it will appear here.
Share your result
Why Length Is the Real Variable
Style names hide the one thing doing most of the visual work. A short boxed beard set to 3mm and the identical style set to 15mm belong to two different faces by the time either one grows in — same name, opposite effect.
Cheek Length Adds Width
Fullness held at the sides broadens the lower face instead.
The Difference Is the Shape
A taper — cheeks shorter than chin, or the reverse — is what turns those two numbers into a line the eye reads as shape.
Guards Are Millimetres in Disguise
Trimmer dials are numbered, not measured, but they translate directly: guard 3 sits close to 9mm on most machines.
Two settings drive that effect, and they're independent of each other: how long the hair sits at the chin, and how long it sits on the cheeks. Pull those apart and a beard style finder can tell you which named shape suits your face — this page assumes you already know that and answers the question the style name leaves blank.
That's why the guidance here runs in millimetres rather than labels. Most trimmer guards map straight onto them: guard 1 lands around 3mm, guard 3 around 9mm, guard 5 around 16mm — figures you can carry straight to the bathroom mirror.
The Full Length Chart, Shape by Shape
Chin length, cheek length, and the gap between them, laid out shape by shape rather than buried in one long paragraph.
Reading the seven face shapes side by side makes the pattern obvious in a way a single result never does: the shapes that call for a wide taper sit at one end, the ones that want cheeks and chin nearly equal sit at the other, and most faces land somewhere between the two rather than at either extreme.
Getting the
Trim Right
A millimetre figure is only a target. What happens between the trimmer and the mirror decides whether you land on it.
Start Longer Than the Target
Go one guard above and work down toward the number. Hair removed can't be put back on.
Trim Dry
Wet hair stretches under the guard, so a beard trimmed while damp finishes shorter than the setting suggests.
Trim Against the Grain
Running the trimmer with the direction of growth leaves more length behind than the guard number implies.
Re-Check Weekly
Growth is even enough that a sharp taper flattens into one uniform length within roughly two weeks of no maintenance.
How It Works
1
Upload Photo
One clear, front-facing shot is all the measurement needs.
2
Face Shape Measured
The same 68 landmark points used across the site's other measurement tools convert your photo into proportions.
3
Advice Matched
Those proportions get matched to written chin- and cheek-length guidance for your specific shape.
4
Take It With You
Three named length options come back, each anchored to exact chin and cheek millimetre settings for your stylist or your own trimmer.
Why Choose
FaceShapesAI?
Advanced AI technology combined with beauty science to give you the most accurate results.
Advanced AI Technology
Trained on millions of faces for high accuracy.
Privacy Focused
Your photos are never stored. 100% secure & private.
Instant Results
Get your analysis in seconds, not minutes.
Personalized Tips
Receive style, haircut & grooming recommendations.
User Friendly
Simple, easy-to-use interface for everyone.
Works for Everyone
Our AI works for all genders, ages, and ethnicities.
Guard Numbers to Millimetres
Trimmer dials are numbered rather than measured, which is exactly why millimetre advice is hard to act on without a conversion chart. Across most common brands: guard 1 sits near 3mm, guard 2 near 6mm, guard 3 near 9mm, guard 4 near 12mm, and guard 5 near 16mm. Anything below guard 1 is a stubble setting, typically running from 0.5mm up to 2mm.
Brands drift from that chart occasionally, so check your own trimmer against a ruler once and you'll know your specific set for good. It's two minutes well spent — the gap between 3mm and 6mm on the cheeks alone is easy to see across a room.
The Taper Is the Whole Technique
Running one length over the entire beard is the single most common mistake, and it's the reason a beard can look like coverage instead of a deliberate shape. Set the cheeks shorter than the chin and a vertical line appears, stretching the face. Set both to the same figure and the beard simply preserves whatever shape was already there.
For a round face, that gap matters more than almost anything else on this page — 3mm at the cheeks against 15mm at the chin does something a flat 9mm everywhere cannot touch. A diamond-shaped face flips the logic entirely: keep the sides as full as the chin, since widening the jaw rather than narrowing it is the point.
None of that holds without upkeep. Hair grows at close to the same rate everywhere on the face, so a beard carefully graded this week reads as one uniform length within a fortnight if it's left alone.
When to Ignore the Numbers
Patchy cheek growth overrides the shape-based number every time. A longer setting there hides gaps that a short one exposes, even on a face where the geometry points toward trimming shorter — visible bare patches lose to coverage, no exceptions.
Hair texture shifts the math too. Coarse or curly growth reads fuller and wider than the same millimetre length in fine, straight hair, so identical settings produce visibly different results on different beards. If your growth runs coarse, shave a millimetre or two off the cheek numbers you're given here.
About This Tool
The guard-to-millimetre chart above comes from an in-house model, not a rented API — Ahsan Fayyaz trained it on real faces and checked it against other face-analysis tools before publishing a single number. It's the same engine powering every face-shape and styling tool on the site. It's an informational styling guide, not medical, clinical, or professional grooming advice, and the millimetre settings it returns are a starting point for your trimmer, not a guarantee of a specific outcome.
Our Growing Suite of AI Face & Style Tools
Explore our powerful AI tools designed to enhance your style and confidence.
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Discover your face shape with AI accuracy.
68-Point Landmark Map
See every point the AI reads on your face.
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Nose Shape Detector
Base width against bridge length, from the front.
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Face Symmetry Test
A region-by-region symmetry breakdown.
Symmetry Mirror & Heatmap
Your face mirrored on both sides.
Golden Ratio Proportions
Three facial ratios measured against phi.
Golden Ratio Phi-Mask
The phi grid drawn over your photo.
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K-pop Look-Alike
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Hairstyle Recommender
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Glasses Frame Finder
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Sunglasses Shape Guide
The right sunglasses for your face.
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Fringe Suitability
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Hair Parting Guide
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Makeup Contour Guide
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Eyebrow Shaping Guide
The brow shape that fits your features.
Beard Length Advisor
How much length balances your jaw.
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Body Ratio Calculator
Waist-to-hip and shoulder ratios.
Outfit Silhouette Guide
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Dress Style Recommender
Dress cuts matched to your proportions.
Universal Size Helper
Translate your measurements across brands.
Got Questions?
Frequently Asked Questions
It reads your face shape from landmark points on an uploaded photo, then converts that shape into a chin-length and cheek-length target in millimetres, plus the reasoning behind the gap between the two.
Lengths, primarily — chin and cheek millimetre settings rather than named shapes. If you want the style-name version of this question, the beard style finder runs on the same face-shape measurement but answers "which beard" instead of "how long."
No. Your photo is processed by the in-house model and deleted from the server immediately after your result is generated. What's left on screen afterward lives only in your browser's cache — refreshing the page clears it permanently, on both ends.
Yes — two free scans a day, no account required.
Two, tracked by browser and IP address. A free account raises the daily limit, and paid plans remove the cap entirely.
Close, but not identical. The guard-to-millimetre chart here reflects common brands; yours may run slightly off from it.
Check your specific guards against a ruler once — most trimmers ship with a printed or online spec sheet too. Once you know your set, the numbers on this page translate directly every time after that.
Dry. Wet hair stretches under the guard, so a beard trimmed damp ends up shorter than the number you set once it dries.
Against it, if you want the guard number to hold. Trimming with the direction of growth leaves more length behind than the setting implies.
About once a week. Growth is even enough across the face that a sharp taper reads as one flat length again within roughly two weeks if it's left untouched.
The gap between your cheek setting and your chin setting. A wide gap — say 3mm on the cheeks against 15mm at the chin — reads as a strong vertical line. A gap of zero just preserves the face's existing shape.
Rounder faces typically get a wider gap between cheek and chin settings, since that gap is what adds the vertical line a round face benefits from most. The exact figures come from your own scan, not a fixed formula everyone shares.
A diamond face is usually narrow through the jaw already, so the goal flips: keeping the cheeks nearly as full as the chin adds width instead of stretching length that face doesn't need.
Not strictly. Coverage beats geometry here — a longer setting on patchy cheeks hides bare spots that a shorter, more "correct" length would expose. Follow your growth pattern first and treat the numbers as a secondary guide.
Yes. Coarse and curly growth reads fuller and wider than the same length of fine, straight hair, so identical millimetre settings look different depending on texture. Shave off a millimetre or two on the cheeks if your growth runs coarse.
Yes. The face-shape measurement reads jawline, cheekbone width, and similar landmarks, none of which depend on facial hair being present, so a clean-shaven photo works the same as a bearded one.
Yes — your result posts as a styled image, no separate screenshot needed.
No. Both daily free scans work without signing up.
No. It's an informational styling tool for entertainment and general guidance, not a substitute for a dermatologist, barber, or other professional's judgment about your specific skin or hair.
Same underlying face-shape measurement, same 68 landmark points, different output. The Beard Style Finder names the shapes that suit your face; this page skips the naming and gives you the chin and cheek millimetre settings directly.
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Get Your Beard Length
Upload a photo and get your chin and cheek settings in millimetres, ready for your trimmer.