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478 landmarks
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Jawline structure index
Gonial angle test: measure your jawline angle in degrees
The gonial angle is the corner of the jaw, where the lower border of the mandible meets its rising posterior border. It is the single strongest structural driver of how defined a jawline reads, and this free jawline angle calculator is an AI face scan that measures it on both sides.
Free basic reports require no credit card, no account, no password. Your image is never uploaded or stored. Analysis happens in your browser and your session data is cleared when you close or refresh the page.
In short
The gonial angle is the angle at the corner of the jaw, measured in degrees. Lower values near 110 produce a squared, defined jawline, higher values near 130 produce a softer oval lower face. Facemap estimates it from surface landmarks on each side separately.
- 3D landmarks
- 4783D landmarks
- Scan time
- ~20sScan time
- Uploads, runs in browser
- 0Uploads, runs in browser
- No account required
- FreeNo account required
Where it is measured
Gonial angle on the landmark mesh.
The overlay is drawn from the same 478 point MediaPipe landmark set Facemap uses on your own scan, so every caliper, axis and node sits on the exact anatomy the measurement is taken from.
Sample reading, Jawline structure index
- Gonial angle
- 122.6°
- Ramus length
- 71.2 mm
- Jaw definition
- 0.88
- Angle class
- Defined
How the scan works
Capture
Guided front-on frame with even light, no upload.
Landmark
478 point mesh placed on your face in real time.
Report
Gonial angle measured, normalised and explained.
What is gonial angle?
The mandibular angle formed at the gonion. Sharper angles produce a more squared jaw, wider angles produce a softer, more oval lower face.
How Facemap measures gonial angle
Facemap fits lines through the jaw border landmarks on each side of the mesh and reports the angle between them, corrected for head yaw so both sides are comparable.
What the typical range looks like
Measured values commonly sit in a broad band around 120 degrees, with a strong sex and ancestry component. A surface scan estimates soft-tissue geometry, not bone, so treat it as an index rather than a clinical figure.
How to read your result
The useful reading is the left-to-right difference and the change over time, both of which are stable when your capture is consistent.
The gonial angle formula: how we calculate it
Interior angle at the jaw corner. Landmark numbers are MediaPipe Face Landmarker indices, and every distance is normalised to your own face so camera distance and image size cancel out.
angle at 172 between 234 and 152, mirrored at 397, then averaged
- Landmarks used
- 234, 172, 152 and 454, 397, 152
- Reference target
- 126 degrees
- Tolerance band
- 16 degrees
Your reading is compared with that published reference on a Gaussian match curve: score = round( 100 x exp( -0.5 x ( (reading - target) / tolerance )^2 ) ), clamped to 1 to 99. Basis for the reference value: cephalometric gonial angle ranges reported in the maxillofacial literature. The headline Attractiveness Score works differently: all readings are corrected for head angle and expression, weighted by confidence and mapped onto a 1 to 100 scale by a model calibrated against a published research set of more than Facemap scans.
Read the full Facemap methodology, including how the 22 measurement categories combine into your Attractiveness Score.
Gonial angle reference table
Gonial angle bands and how each one reads.
- 105 to 115Sharp
Squared, highly defined jaw corner
- 115 to 125Typical
The most commonly measured band
- 125 to 135Open
Softer, more oval lower face
- Above 135Wide
Minimal visible jaw corner
What a soft-tissue gonial angle can and cannot tell you
A camera sees skin, not bone. Facemap measures the visible jaw contour, so the result is a soft-tissue index that tracks the underlying skeletal angle closely but is also affected by body composition and tissue laxity. It is reliable for comparing your own scans over time, and it is not a substitute for a cephalometric measurement.
Why left and right jaw angles differ
A few degrees of difference between sides is ordinary. Larger gaps usually come from one of the following.
- Head yaw during capture, corrected but not eliminated
- Habitual chewing side and masseter development
- Genuine skeletal asymmetry, visible in your symmetry score too
- Sleeping position and short-term tissue swelling
Reading gonial angle with the rest of your lower face
Jaw definition is a combination, not a single number. Pair your gonial angle with facial thirds to see whether a soft-reading jaw is really an angle issue or a lower-third length issue, and with midface ratio to understand overall lower-face proportion.
The gonial angle formula, step by step
The jawline angle calculator fits two lines to your jaw border and reads the angle between them, on each side separately.
- Locate the gonion, the lower border of the mandible and its posterior border
- Fit a line along the lower border of the jaw
- Fit a second line along the rising posterior border
- Measure the angle between the two lines at the gonion
- Correct for head yaw and repeat for the opposite side
Your reading
Measure your gonial angle in about twenty seconds.
The scan runs in your browser. Nothing is uploaded, and free basic reports need no account.
Questions
Gonial angle test: frequently asked questions
Is this the same as a cephalometric x-ray measurement?
No. Facemap measures the visible surface of your face, so it reports a soft-tissue index rather than a skeletal angle.
What is a good gonial angle?
Most measurements fall between 115 and 125 degrees. Sharper angles read as more defined, wider angles read as softer, and both are common across sexes and ancestries.
Can the scan tell me how to change my jawline?
No. Facemap describes structure and does not recommend procedures or treatments.
Does body fat affect the gonial angle reading?
Yes, because the scan follows the visible contour. This is why repeat scans over time are more informative than a single reading.
Do I need to turn my head for a jaw measurement?
No. Stay straight on. The scan derives both jaw borders from the same 3D mesh and corrects for small amounts of yaw.
How is the gonial angle formula worked out?
Facemap fits a line along the lower jaw border and a second line along the posterior border, then measures the angle between them at the gonion, corrected for head yaw, on each side.
Is the gonial angle test an AI face scan?
Yes. It runs Google's MediaPipe Face Mesh machine learning model in your browser with 478 3D landmarks, nothing uploaded, so the angle is deterministic geometry rather than a subjective read.
Related tools
Measurements that read alongside gonial angle.
Vertical proportion balance
Facial thirds face scan
The face is divided into three equal vertical zones: hairline to brow, brow to nose base, and nose base to chin. We measure how evenly your landmarks fall within each.
Width-to-height compactness
Midface ratio face scan
The ratio of midfacial width to midfacial height, derived from cheekbone and nasal landmarks to describe central-face compactness.
Bilateral landmark balance
Facial symmetry face scan
We compare 478 corresponding landmarks across the vertical midline of your face, region by region, to quantify how closely each side mirrors the other.
Every tool