Canthal tilt calculator: place the corners yourself
Canthal tilt is the angle from the inner to the outer corner of an eye relative to a horizontal reference. This free manual calculator lets you mark both corners on each eye and inspect the photo angles in degrees. It runs in your browser without uploading your photo. It does not infer attractiveness, diagnose anything, or automatically correct your head position.
Your photo stays in this tab. Nothing is uploaded. This is a manual photo-angle tool, not an automatic face assessment.
Use a straight-on, level photo in even light. You will place the inner and outer corner of each eye yourself. No sign-up or model download needed.
How to use the calculator
- Choose a clear, straight-on photo at eye level with your head level. Use the capture checklist.
- Select each of the four named points and tap the exact eye corner in the photo. Initial markers are placeholders, not detections.
- Move the points with the arrow keys for fine adjustment. Left and right refer to the photo, which may be mirrored.
- Keep the reference at 0° for the photo horizontal, or document any manual rotation. Read both angles only after placing all four points.
Which points count?
The inner corner is the visible junction of the upper and lower eyelids nearest the nose; the outer corner is the junction nearest the temple. Mark those corners, not the pupil, brow, eyeliner wing or an arbitrary point on the lid. If they are obscured, choose a clearer photo. The canthal-tilt guide explains the definition and its limits.
The calculation is inspectable
At a 0° reference, the calculator uses arctan((inner-corner height − outer-corner height) / horizontal distance between corners), converted to degrees. Image coordinates increase downwards, so a higher outer corner produces a positive number. A manually rotated reference is applied with the appropriate sign for each side. The displayed tenth of a degree is formatting, not proven accuracy.
What this reading cannot establish
- A turned or tilted head can change the photo angle. This tool does not estimate or remove that pose.
- The visible corner can be hard to place. Compare multiple placements and retakes rather than treating one number as exact.
- Positive, neutral and negative describe direction, not beauty, health, or a need to change your face.
- This manual browser calculator is separate from the app’s eye-region measurements. It does not claim the app measures anatomical canthal tilt.
Common questions
Is this canthal-tilt calculator free and private?
Yes. It measures points you place manually in your browser, with no account, model download or photo upload. Clear the photo or leave the page to remove it from the tool.