Top Third: What It Measures and How FaceIQ Labs Calculates It

Key facts

• Formula: Top Third = (hairline-to-brow height ÷ hairline-to-chin height) × 100.
• The Top Third is a front-view measurement in the Facial Thirds group of FaceIQ Labs' Harmony guides.
• Lower value: the forehead takes up less of the face height. Higher value: it takes up more.
• Worked example: a 60-unit forehead on a 180-unit face gives 33.3%; a 66-unit forehead on the same 180-unit face gives 36.7%.
• The example values are not a target range and are not measurements of the guide's schematic.
• A fringe, a receding hairline or an incorrectly marked brow level can change the result without any change in facial bone structure.
• The facial thirds idea grew out of artistic proportion canons and anthropometry; Farkas and colleagues tested those rules in 1985.
• FaceIQ Labs' Harmony pillar compares 70+ facial ratios and angles to ideal ranges adjusted for gender and ethnicity.
• FaceIQ Labs weights Harmony roughly 60% from the front photo and 40% from the side photo.

What is the Top Third measurement in FaceIQ Labs?

The Top Third is a front-view Harmony measurement in FaceIQ Labs that expresses forehead height as a percentage of full face height. It belongs to the Facial Thirds group of Harmony guides and is one of the 70+ facial ratios and angles the Harmony pillar compares against ideal ranges adjusted for gender and ethnicity.

How does FaceIQ Labs calculate the Top Third?

FaceIQ Labs calculates the Top Third by dividing hairline-to-brow height by hairline-to-chin height and multiplying by 100. The numerator is forehead height and the denominator is full face height. The guide's schematic labels these A (forehead height) and B (full face height), and FaceIQ uses photographed brow landmarks to divide the face.

Why does the Top Third matter?

• In FaceIQ Labs' Harmony guide, the Top Third matters because the forehead frames the eyes and changes how height is distributed across the face.
• A larger upper third can make the same eyes, nose and jaw occupy a smaller share of the overall outline.
• Lower: the forehead takes up less of the face height.
• Higher: the forehead takes up more of the face height.

Where does the Top Third idea come from?

The Top Third comes from classical facial thirds, which grew out of artistic proportion canons and later anthropometry, the measurement of human form. Farkas and colleagues tested those rules in 1985 in 'Vertical and horizontal proportions of the face: revision of neoclassical canons', which tested nine traditional proportion rules against measured faces. FaceIQ Labs notes that classical rules are not universal targets, and that its score weights and reference ranges are model settings these papers do not collectively validate.

What is a worked example of the Top Third calculation?

In FaceIQ Labs' worked example, a forehead spanning 60 units on a face 180 units tall gives a Top Third of 33.3%. Keeping the full height at 180, a 66-unit forehead gives 36.7%. These values only explain the calculation; they are not a target range and not measurements of the schematic.

What can distort a Top Third result?

Hairline placement can change a Top Third result in FaceIQ Labs without any change in facial bone structure. A fringe, a receding hairline or an incorrectly marked brow level can shift the percentage. FaceIQ Labs offers landmark mapping with manual landmark review and editing tools, and recommends photos taken from six feet away with the back camera at 2x zoom, at eye level, with even lighting and a neutral expression.

Does FaceIQ Labs give an ideal Top Third range?

The FaceIQ Labs Top Third guide does not state a numeric ideal range. Its example values of 33.3% and 36.7% only illustrate the calculation. FaceIQ Labs' Harmony pillar compares its 70+ ratios to ideal ranges adjusted for gender and ethnicity, but this guide does not list the Top Third range.

Frequently asked questions

What does the Top Third measure?

It measures forehead height as a percentage of full face height: hairline-to-brow height divided by hairline-to-chin height, multiplied by 100.

Is the Top Third measured from the front or side photo?

The Top Third is a front-view measurement in FaceIQ Labs' Harmony guides.

What does a higher or lower Top Third value mean?

A lower value means the forehead takes up less of the face height. A higher value means the forehead takes up more of the face height.

Can my hairstyle change my Top Third result?

Yes. A fringe, a receding hairline or an incorrectly marked brow level can change the result without any change in facial bone structure.

Does Farkas's 1985 study validate FaceIQ Labs' scoring?

No. The 1985 study by Farkas and colleagues tested nine traditional proportion rules and is background history for facial thirds. FaceIQ Labs says its score weights and reference ranges are model settings that these papers do not collectively validate.