Gonial angle calculator

01

The gonial angle is the corner where the horizontal body of your jaw turns up toward the ear. Studies that measure it on side X-rays and profile photos put most adults around 110° to 130°. This tool reads it from a front photo, which projects the same jaw wider, so it grades on the front-photo range of 126° to 142°. Below 126° in a front photo the corner reads sharp and defined. Inside the range it reads typical, which covers most faces. Above 142° the edge between jaw and neck starts to read soft, and that is where it costs definition in photos.

02

A left-right difference under 3 degrees is universal and invisible. Between 3 and 6 it is measurable but rarely noticed by anyone else. Past roughly 6 degrees the asymmetry becomes visible in a straight-on photo, and if it appeared recently rather than being lifelong, that is a reason to see a clinician, since bite problems and jaw joint issues can produce it.

03

The angle itself is bone, and no exercise, chewing, or posture changes it. What changes how it looks is the tissue over it: body fat, water retention, and masseter bulk. If your reading is inside 126° to 142° and your jaw still reads soft, the lever is almost always body fat, not bone; the FFMI calculator estimates your body fat from a tape measure and shows how much muscle sits under it. Above 142° in a front photo, the first options are the ones you control: a beard or stubble line that draws the jaw edge, a haircut that frames the lower face, upright posture so the jaw does not fold into the neck, and lower body fat. Changing the bone itself is a conversation for a surgeon, not an app.