Free tool · runs in your browser
Eyebrow Mapping Tool
The three lines a brow artist draws before shaping, placed on your own face: from the outer edge of each nostril through the inner eye corner (where the brow should start), the pupil (the arch) and the outer eye corner (the tail). The tool then measures where your brows actually start, peak and end against those lines, in millimetres.
Drop a photo, paste one, or choose a file
Straight-on, whole face visible, even light. JPG, PNG or WebP.
Runs in your browser. Your photo never leaves your device.
How it is measured
Three pencil lines from the nostril, measured with your iris as the ruler.
Brow mapping is done with a pencil held against the side of the nose and pivoted to three angles. The tool finds the same pivot (the outer nostril), the inner eye corner, the pupil and the outer eye corner among 478 landmarks, and draws the three lines across each brow. It traces the brow's centre line and finds its head, highest point and tail, then reports the gap to each line. A photo has no scale, so millimetres come from your iris, which is close to 11.7 mm across in most adults.
- Start (gold)
- Nostril → inner eye corner. The brow head usually sits on or just inside this line.
- Arch (blue)
- Nostril → pupil, looking straight ahead. The common guide puts the peak on or just outside it.
- Tail (green)
- Nostril → outer eye corner. The tail ends near where this line crosses the brow.
- Tail height
- Guides keep the tail level with or above the head; a lower tail reads tired.
Measure it yourself
How to map your eyebrows with a pencil
The manual method the tool reproduces. You need a mirror, a straight brow pencil and a light hand.
- 1Face the mirror straight on, brows relaxed, hair off the forehead.
- 2Rest the pencil against the outer edge of one nostril and line it up with the inner corner of the eye on the same side. Mark where it crosses the brow: the start.
- 3Keep the base on the nostril, look straight ahead, and pivot the pencil across the centre of the pupil. Mark the arch.
- 4Pivot again to the outer corner of the eye. Mark the tail.
- 5Repeat on the other side and compare: the two sets of marks rarely match exactly.
Skip the ruler: the free tool above does it from one photo in about 30 seconds ↑
Sources
What this is based on.
The measurement and its reference ranges come from published research. Studies use different methods and populations, so compare your number with the range shown on this page rather than with other tools.
- 1.
Gunter JP, Antrobus SD (1997). Aesthetic analysis of the eyebrows. Plastic and Reconstructive Surgery. PubMed 9180703
Aesthetic analysis of where the brow starts, peaks and ends, and how its shape is judged.
- 2.
Rüfer F, Schröder A, Erb C (2005). White-to-white corneal diameter: normal values in healthy humans obtained with the Orbscan II topography system. Cornea. PubMed 15778595
Corneal diameter averaged 11.71 mm in adults: the scale behind the millimetre readings.
Our own data: how much each reading moves when the same face is photographed again is published on the methodology page. How we choose sources.
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FAQ
What is eyebrow mapping?+
The placement step before waxing, threading, tinting, lamination or microblading: three lines that set where the brow starts, peaks and ends for your face. Everything between those points is styling choice.
Why are my two brows different?+
Almost everyone's are. Brows sit on muscle that moves with expression, and most faces are slightly asymmetric. Differences of 1–2 mm are normal and usually invisible.
What does 'inside the line' mean?+
Closer to the nose than the line. A start inside the line can make the eyes look closer together; a tail inside the line can make the eye look shorter.
How accurate are the millimetres?+
They use the iris as a ruler (about 11.7 mm in most adults), so they carry a few percent of error from that alone. Use them to compare sides and to plan, not as a medical measurement.
Should I look at the camera?+
Yes. The arch line goes through the pupil while looking straight ahead; looking at the screen instead of the lens moves the pupils slightly.
Is my photo uploaded?+
No. Everything runs in your browser.
One reading here.
Nineteen in the app.
A controlled scan, every reading against its ideal band, bone vs trainable, a plan, and a 3D model on Face ID iPhones.