Chin width: one term, at least three different landmarks.

Chin width most often means the side-to-side width of the chin button itself — the narrow lower point of the jaw, below and medial to the jaw's back corners:

• Narrower chin — discussed in forum threads as reading more tapered or pointed.
• Wider chin — discussed as reading more square or blocky, sometimes flagged as crowding the mouth above it.

That's a different span from cheekbone ratio's jaw-width denominator, which is measured corner-to-corner at the jaw's back angles (bigonial width) — well lateral to the chin button itself.

Distinct looksmax.org threads quote chin width against at least three different reference spans, and rarely say so explicitly:

• One rule cites chin width as roughly one-third of bigonial width — with an average male bigonial width of about 96mm, that implies roughly 32mm, a figure other posters in the same discussion argue reads too narrow.
• A separate thread compares chin width directly against mouth width instead, arguing a chin should not exceed the mouth as a rough ceiling — a completely different reference span from bigonial width.
• A third framing treats bigonial width itself as a stand-in for "chin width," despite bigonial width being the jaw's back-corner span, not the chin button's own width.

A single quoted millimeter or ratio figure for "chin width" is only meaningful once you know which of these three spans that particular thread meant — they are not interchangeable, and a number correct for one is not automatically correct for another.

Every measurement Mogalytics reads is a ratio — a proportion between two on-face distances, like cheek width relative to jaw width. Ratios cancel out unknown camera distance and lens, which is exactly why a live camera feed can read them at all. An absolute width in millimeters is a different problem on top of the landmark-ambiguity one above:

• It requires knowing the real-world scale of the image — a fixed, known camera-to-face distance, a calibration object of known size in frame, or stereo depth sensing.
• A single flat webcam frame at an unknown distance can't resolve that scale on its own — the identical pixel gap between two landmarks represents a different number of real millimeters depending on how close you're sitting.

So even a tool that picked one of the three spans above and placed its landmarks perfectly still couldn't hand back a trustworthy millimeter figure without a calibration step most self-rating tools, Mogalytics included, don't run at all.

Mogalytics does not compute or display a chin width in millimeters. The closest existing pages are:

• Cheekbone ratio — uses bigonial (jaw-corner) width as its own denominator, the span some chin-width threads conflate with the chin itself.
• Jaw ratio — the closest of the six measurements Mogalytics reads live, a height proportion rather than a width.

Mogalytics makes no claim that either ratio approximates a chin width in millimeters, or of parity with any other site's specific chin measurement.

Chin width sits next to two of the six measurements Mogalytics tracks, and shares its scale problem with other pages on this site:

• Cheekbone ratio — the closest camera-read analog, using the jaw-corner span some threads confuse with chin width.
• Jaw ratio — a height proportion instead, sensitive to chin pitch.
• Chin-to-philtrum ratio — a different chin measurement entirely, a vertical proportion rather than a width.
• Philtrum length and interpupillary distance — two other absolute mm figures with the same monocular scale-ambiguity limitation.
• Gonial angle — a related jaw-corner measurement read as an angle from a side profile, not a frontal width.
• Chin projection — a profile depth reading of the same chin, not a frontal width, and its own separate forum dispute.