Canthal Tilt Calculator: Is Your Canthal Tilt Positive or Negative?

Canthal tilt is the angle of the line from the inner corner of the eye (the medial canthus) to the outer corner (the lateral canthus), measured against a horizontal reference. When the outer corner sits higher than the inner corner the tilt is positive; when it sits lower the tilt is negative; when the two are level it is neutral.

The angle is also called the palpebral fissure inclination or eye tilt. It is one of the features people mean when they talk about hunter eyes and almond-shaped eyes, and a downward angle is what is usually described as negative canthal tilt.

MediaPipe Face Landmarker finds 478 landmarks on your face in your browser, including the inner and outer corner of each eye. The calculator first rotates the landmarks so that the line between your two iris centers is horizontal. That removes head roll, so tilting your head in the photo does not tilt the reading.

For each eye it then measures the angle of the inner-to-outer corner line against that level reference. A positive number means the outer corner is higher. The two eyes are reported separately and averaged, and the ±1° neutral buffer keeps tiny landmark variations from flipping the band. The bands match those used by the Hunter Eyes Test.

Published studies commonly report average adult canthal tilts a few degrees above zero, with results that differ by population, age, sex and measurement method. For example, one study of young South Indian adults reported averages of about 5° in men and 6° in women. A group average describes the group, though, and does not make an individual reading right or wrong.

Negative and neutral tilts are common and are not a health problem in themselves. Canthal tilt can change slightly with age as the tissues around the eyes relax. A photo reading also cannot diagnose an eyelid condition; if your eyelid position has changed or bothers you, ask an eye specialist.

Small angles are sensitive to how a photo is taken. For a reading you can compare over time:

• Look straight into the camera with the lens at eye level, not above or below.
• Keep your eyes open and relaxed. Smiling and squinting raise the lower lid and push the outer corners up.
• Avoid wide-angle close-ups; hold the camera at arm's length or further.
• Use even front light so both eye corners are clearly visible.
• Remove glasses and keep hair away from the outer corners.
• Take two or three photos and compare the readings; differences under 1° are within normal variation.

A positive canthal tilt is one of the traits associated with hunter eyes, together with a narrow eye opening, more upper-lid coverage of the iris and a low brow sitting close to the eye. Canthal tilt alone does not decide it. For the full set, the Hunter Eyes Test measures all four and adds a hunter eyes match score, and the guide to hunter eyes vs prey eyes explains the terms.

Eye angle is a single measurement. For the balance between the two sides of your face, use the Face Symmetry Test. For proportions such as the facial thirds and the golden ratio, use the Golden Ratio Face Test. The full face report, available after any reading, combines symmetry and proportions in one place.