The four axes the analysis measures

Upper-to-lower lip ratio. Upper vermilion height divided by lower vermilion height. The published reference band sits at 1:1.5 to 1:2; ratios outside the band shift the read toward top-heavy or bottom-heavy.

Total fullness index. Combined vermilion area normalized by lower-face area. Higher index reads as fuller; lower index reads as thinner. Fullness interacts with sex dimorphism in how it is rated.

Cupid bow definition. The depth and sharpness of the central upper-lip peak relative to lip width. Strong definition reads as heart-shaped; soft definition reads as straight or wide.

Oral commissure angle. The resting angle at the corners of the mouth. Positive (upturned) reads as approachable; negative (downturned) reads as serious. This is the most habit-modifiable input over a 30 to 60 day window.

The seven lip shape categories

Full and balanced

Ratio in the 1:1.5 to 1:2 band, fullness above the population median, neutral commissure. The reference shape. Most consistently rated as attractive across raters.

Thin and balanced

Ratio in the reference band, fullness below the median, neutral commissure. Reads as understated. Defined lip-line work amplifies the existing geometry.

Heart-shaped

Defined cupid bow, fuller lower lip, ratio toward 1:2. Considered a feminine-coded shape in the rating literature. Lip-line emphasis on the bow amplifies the read.

Top-heavy

Ratio below 1:1.3 (upper lip relatively full). Less common shape. Reads as a distinctive signature; balancing makeup approaches focus on lower lip enhancement.

Bottom-heavy

Ratio above 1:2.5 (lower lip dominates). Common shape. Pairs well with strong chin projection; weak chin projection produces a soft lower-face read.

Downturned

Negative commissure angle at rest. Often a habit pattern that responds to conscious lower-face relaxation over 30 to 60 days. Makeup corner-lift techniques produce immediate visual change.

Wide and straight

Low cupid bow definition, similar upper and lower fullness, wide horizontal line. Reads as classical and balanced. Makeup goal is usually to add subtle peak definition.

The free levers that move lip read by a measurable amount

Hydration. Consistent water intake plus a non-stripping lip barrier produces visible vermilion volume increase of 5 to 10 percent within 7 to 10 days. Chronic dehydration is the most common cause of apparent lip thinning in adult faces.

Commissure habit. Resting expression sets the corner angle over months. Conscious lower-face relaxation (lips parted, jaw unclenched, tongue resting on roof of mouth) over 30 to 60 days shifts the resting commissure measurably. This is the single largest free intervention on lip read.

Lip-line restoration. The pink-lip line definition that often hides under chapping returns within 14 to 21 days of gentle exfoliation plus barrier repair. The defined lip line increases visible vermilion area without changing the underlying tissue volume.

Honest limits

  • The underlying lip shape is genetic and stable. Soft-tissue levers move vermilion volume by 5 to 15 percent; they do not change the shape category.
  • Filler can shift the shape category and ratio but is reversible only with hyaluronidase and carries documented complication rates. Outside the scope of this analysis.
  • Day-to-day water retention shifts apparent lip volume by 5 to 10 percent. Use well-rested morning photos for the stable read.
  • The cupid bow definition does not change without surgery. Makeup techniques shift the visible bow by adding contrast.
  • Lip shape interacts with chin projection and lower-third length. The full report shows all three together.

Lip ratio in 60 seconds — the honest read

The episode as straight text — no fluff, no dodge:

Is your top lip too thin? Before you decide, let's measure what a photo actually reads.

Lip ratio compares the height of your upper lip to your lower lip, at the center of your mouth.

A commonly cited range favors a slightly fuller lower lip. That is a convention from aesthetics literature, not a law.

Purse or press your lips even slightly, and the ratio changes. Expression moves this read a lot.

Is it fixable? A little. The base shape is genetic. Hydration and gentle exfoliation make lips read fuller for hours, not forever.

In photos, a relaxed mouth is the honest lever. Tension flattens the upper lip and skews the number.

See how yours measures. One of seventeen measurements, free, at realsmile.online.

Measure your lip ratio free →·all 17 measurements — series hub

Lip shape analysis FAQ

What does a lip shape analysis actually measure?+
A clean lip analysis returns four measurable axes. First, upper-to-lower lip ratio: the vermilion height of the upper lip divided by the lower lip. Second, total fullness: the combined vermilion area as a fraction of lower-face area. Third, cupid bow definition: the depth and sharpness of the central upper-lip peak, normalized against the lip width. Fourth, oral commissure angle: the resting angle at the corners of the mouth, positive (corners up) reads as approachable, negative (corners down) reads as serious. The combination of the four axes places the lips into one of seven shape categories: full and balanced, thin and balanced, heart-shaped, top-heavy, bottom-heavy, downturned, or wide and straight.
What is a "good" upper-to-lower lip ratio?+
The ratio most consistently rated as attractive in the published research sits between 1:1.5 and 1:2 (upper lip to lower lip), per cosmetic-research norms derived from rating panels. A 1:1 ratio reads as top-heavy on many faces; a ratio above 1:2.5 reads as bottom-heavy. The aesthetic literature on lip fillers explicitly targets this band when restoring proportion. The free analysis returns your measured ratio and the percentile against the published norms. Most natural lips that are described as "balanced" sit within this band; the band is descriptive, not prescriptive.
Why does lip shape affect overall attractiveness?+
Three published mechanisms connect lip shape to attractiveness ratings. First, neoteny: fuller lips correlate with neotenous facial features and are rated as more attractive in female faces (Cunningham, 1986). Second, sex dimorphism: lower fullness with defined philtrum columns reads as masculine; higher fullness with softer columns reads as feminine, per Said & Todorov (2011). Third, expression cues: positive resting commissure angle reads as approachable and trustworthy (Willis & Todorov, 2006), interacting with attractiveness ratings beyond geometry alone. The shape and the expression cue interact; pure fullness without favorable commissure angle does not move the read as much as the combination.
Can I change my lip shape without filler?+
Bone structure (maxillary projection, dental arch shape) does not change in adults; this sets the lip platform. Vermilion volume can shift by 5 to 15 percent through three soft-tissue levers. Hydration: chronic dehydration produces visible vermilion thinning that reverses with consistent water intake. Lip care: regular gentle exfoliation and barrier repair (occlusive balm with non-irritating formulation) restores the pink-lip line definition that often hides under chapping. Resting expression: a habitual frown sets the commissure angle downward over time; conscious relaxation of the lower face shifts the resting angle measurably over 30 to 60 days. None of these change the underlying lip structure; all change the visible read.
Are heart-shaped lips actually a desirable shape?+
In the published research, heart-shaped lips (pronounced cupid bow with full lower lip) are rated as attractive in female faces and neutral in male faces. The shape combines neotenous fullness in the lower lip with definition in the upper. The shape is genetic; the cupid bow depth is not changeable without filler or surgery. The shape is not universally preferred; in raters preferring sex-dimorphic features, a less defined cupid bow on male faces and a more defined cupid bow on female faces is the dominant pattern. The free analysis returns whether your lips fit the heart-shaped category and where they sit on each axis.
How does lip shape interact with the rest of the face?+
Lip shape is part of the lower-third metric set on the 17-metric scan, alongside chin projection, mandibular angle, and submental contour. A full lip with weak chin projection reads as soft. A full lip with strong chin projection reads as balanced. A thin lip with strong chin projection reads as severe. The full report scores lip shape in the context of the other lower-third metrics so the recommendations are calibrated to the overall geometry rather than the lips alone.
Why does my lip shape look different at different times?+
Three day-to-day inputs shift apparent lip shape. Hydration changes vermilion volume by 5 to 10 percent within hours. Recent eating, drinking, or talking flushes the lips with blood and increases apparent fullness temporarily. Time-of-day water retention from sodium and sleep position changes the lower-face contour. The 17-metric scan normalizes for these by using ratio-based measurements (relative proportions rather than absolute dimensions). The shape classification is stable across well-rested mornings; same-day variation should be interpreted as measurement noise.
What does the $14.99 PDF unlock for lip shape?+
The free analysis returns the dominant shape category and percentile on each of the four axes. The $14.99 report adds a written interpretation of how your specific lip configuration interacts with your chin, midface, and overall lower third, the makeup and grooming recommendations calibrated to your specific shape, and a 30-day action plan for the hydration, lip-care, and expression levers that can shift the read by a measurable amount.

Four axes. Seven shapes. Lower-third recommendations calibrated to yours.

Unlock the lip-shape report.

$14.99 unlocks the full 17-metric PDF: four-axis values with percentiles, lip-shape interpretation in lower-third context, and 30-day action plan.

Unlock The Report — $14.99 →or try the free score first

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Related Tools

→ feminine face score→ masculine face score→ jawline test→ upper-to-lower lip ratio — glossary→ facial thirds test→ looksmaxxing test — full 17-metric report→ cupid's bow — what it means→ philtrum — glossary→ lip ratio is one of the 17 measurements — series hub