The appearance of the lips depends mainly on their width, the height of the vermillion, the ratio between upper and lower lip, the shape of the Cupid's bow, the length of the philtrum and their profile projection.
To measure them, the face must be at rest, lips naturally joined without tightening them. The frontal photograph must be taken without smiling and the profile photograph with the head in a neutral position.
1. The general shape of the lips
a. The main landmarks
Vermilion corresponds to the visible colored part of the lips.
The stomion is the point in the middle of the line where the two lips meet.
The labial superius is the highest central point of the upper vermilion, in the hollow of Cupid's bow.
The labial inferius is the lowest central point of the lower vermilion.
The cheilions correspond to the two commissures, that is to say the corners of the mouth.
The subnasal corresponds to the central point where the base of the nose meets the upper lip.
Finally, the two crista philtri correspond to the two peaks of Cupid's bow. These landmarks are used in anthropometry to measure the width of the mouth, the vermilion and the philtrum.
b. Upper lip height
The visible height of the upper vermilion is measured vertically in the middle of the mouth:
labial superius → stomion
This measurement therefore does not include the philtrum.
In a study of 300 young Caucasian male models, the upper vermilion measured an average of 5.9 mm.
A very thin upper lip greatly reduces this measurement. A thick upper lip increases it.
The absolute height, however, remains less important than its proportion with the lower lip and the width of the mouth.
c. Lower lip height
The lower vermilion is measured:
stomion → labial inferius
In the same sample of 300 men, it measured on average 11.15 mm, almost twice the height of the upper vermilion.
The lower lip is therefore generally higher and more voluminous than the upper in the desired masculine shape.
2. The relationship between the two lips
a. Lower-to-Upper Lip Ratio
The most used ratio directly compares the height of the two vermilion:
height of lower vermillion ÷ height of upper vermillion
A value of 1 means that both lips are exactly the same height.
A value of 1.5 means the lower lip is 50% higher.
A value of 2 means it is twice as high.
References used for male faces generally place this ratio between approximately 1.4 and 2, with 1.5 to 1.6 frequently presented as a central value.
The study on 300 male models gives:
11.15 ÷ 5.9 = 1.89
This value shows that a ratio close to 1.8 to 1.9 can also work very well in humans.
We can therefore retain a general area around 1.5 to 2, with around 1.6 to 1.9 as a particularly interesting benchmark.
However, there is no single universal proportion. A recent Chinese study, for example, found a preference for a ratio close to 1:1 in manipulated male images.
b. Total lip thickness
We can also add the two vermilion:
labial superius → labial inferius
In the sample of 300 male models:
5.9 + 11.15 = 17.05mm
for a mouth approximately 51 mm wide.
The total height/width ratio was therefore close to:
17.05 ÷ 50.98 = 0.33
In other words, the total height of the vermilion was about a third of the width of the mouth.
An experimental Chinese study instead found a male preference for an aspect ratio close to 1:2.5, or approximately 0.40.
A coarse zone around 0.33 to 0.40 therefore makes it possible to describe sufficiently present lips without becoming extremely thick in relation to their width.
3. The width of the mouth
a. Absolute width
The width of the mouth is measured between the two corners:
left cheilion → right cheilion
In the study of 300 male models, the average width was 50.98 mm.
The absolute value naturally depends on the size of the face. It is therefore preferable to compare this width to the nose and jaw.
b. Mouth-to-Nose Ratio
The width of the nose is measured between the two alares, that is to say the most lateral points of the wings of the nose.
The ratio is:
cheilion-cheilion width ÷ alare-alare width
An area around 1.45 to 1.65 is frequently used, with around 1.5 to 1.6 as the central value. Some recent systems extend the range to around 1.8.
With a 35mm nose and a 54mm mouth:
54 ÷ 35 = 1.54
The mouth is therefore approximately 54% wider than the nose.
Below about 1.4, the mouth becomes relatively narrow compared to the nose. Above about 1.7 to 1.8 it becomes particularly wide.
c. Mouth-to-Bigonial Ratio
It is also possible to compare the mouth to the width of the jaw.
The bigonial width corresponds to the distance between the two gonions, approximately the two lateral angles of the mandible.
The ratio is:
cheilion-cheilion width ÷ bigonial width
An experimental study on attractiveness found a mouth representing approximately 1/2.5 of the bigonial width as the preferred proportion:
1 ÷ 2.5 = 0.40
or around 40%.
The ratios used for male faces are generally around 0.40 to 0.48.
A central value around 0.42 to 0.45 therefore constitutes a good benchmark.
A narrow mouth compared to a wide jawline can give the appearance of being concentrated in the center of the face. A sufficiently wide mouth better accompanies a large mandibular width.
4. The philtrum and Cupid’s bow
a. Philtrum length
The philtrum corresponds to the part located between the base of the nose and the upper edge of the vermillion.
Its central height is measured:
subnasal → labial superius
In the study of 300 male models, the height of the philtrum was on average 15.82 mm.
The absolute value, however, is strongly dependent on the size of the face.
A very long philtrum increases the space between the nose and the mouth and visually lowers the mouth into the lower third. Conversely, a short philtrum brings the upper vermilion closer to the nose.
b. Philtrum in relation to the upper lip
An interesting comparison is to divide the length of the philtrum by the height of the upper vermilion:
subnasal-labial superius ÷ labial superius-stomion
In the sample of male models:
15.82 ÷ 5.9 ≈ 2.68
The philtrum was therefore approximately 2.7 times higher than the upper vermillion.
A zone around 2.5 to 3 thus constitutes a useful masculine benchmark.
A very high ratio corresponds to a long philtrum associated with a small upper lip. A low ratio corresponds to either a short philtrum or a very thick upper lip.
c. Width of Cupid's Bow
The width of Cupid's bow is measured between its two vertices:
crista philtri left → crista philtri right
In the previous male sample, this width was approximately 14.2 mm for a total mouth width of approximately 51 mm.
The ratio was therefore:
14.2 ÷ 51 ≈ 0.28
The central part of Cupid's bow was approximately 28% of the total width of the mouth.
A larger width produces a more spread out Cupid's bow. A small width concentrates the two vertices more in the middle.
d. Cupid's Bow Angle
The central angle is used to measure how marked Cupid's bow is.
We place the apex of the angle at the labial superius, that is to say at the central hollow, then we draw a line towards each of the two crista philtri.
The angle is therefore:
crista philtri left → labial superius → crista philtri right
The smaller the angle, the more pronounced the Cupid's bow. The closer it gets to 180°, the flatter the top edge becomes.
Among the 300 male models studied, the average angle was 138.3° with a standard deviation of around 8°.
A zone around 130 to 145° therefore constitutes a good benchmark for an arc that is visible without being extremely sharp.
5. The vertical position of the mouth
a. Nose-mouth-chin ratio
The mouth should also be located correctly in the lower third.
One method is to compare the distance between the base of the nose and the mouth with that between the mouth and the bottom of the chin.
We measure:
subnasal → stomion
then:
stomion → chin
The ratio is:
stomion-chin ÷ subnasal-stomion
An eye-tracking study on labial proportions found the most attractive configuration to be a mouth-chin distance approximately twice the nose-mouth distance.
The benchmark is therefore approximately:
2:1
The mouth is thus about a third of the distance between the base of the nose and the chin.
A low ratio indicates a relatively low-lying mouth. A high ratio indicates a mouth relatively close to the nose with a lot of height under the mouth.
b. Philtrum and chin
Some systems use a “chin-to-philtrum ratio” instead.
The definition must be clarified, because several variants are circulating. One method is to compare the distance between the bottom of the lower lip and the bottom of the chin to the length of the philtrum:
labial inferius → chin
divided by:
subnasal → labial superius
Ranges around 2 to 2.5 are often used, with some classifications going up to around 2.75.
This ratio is, however, not interchangeable with the previous subnasal-stomion/stomion-chin ratio, because the starting points are not the same.
6. The corners and the line of the mouth
a. Straight, rising or descending commissures
The corners may be located higher, at the same level or lower than the center of the oral cleft.
On a frontal photograph at rest, we draw a horizontal line passing through the stomion then we look at the position of the two cheilions.
Cheilions above the stomion: slightly rising corners.
Cheilions approximately at the same level: straight mouth.
Cheilions below: descending corners.
A straight or slightly rising line is generally preferred.
A sharp descent of the corners creates more of an appearance of a sad or tense expression, even at rest.
There is no sufficiently standardized angular range to justify a precise ratio. Qualitative measurement is therefore more useful.
b. Horizontality of the mouth
We must distinguish the curvature of the corners from the general inclination of the entire mouth.
The latter is measured by drawing a line between the two cheilions and comparing this line to the horizontal.
In the study of 300 male models, the average obliquity was only around 1°.
A generally horizontal and symmetrical mouth therefore constitutes the reference.
A significant inclination to one side corresponds more to an asymmetry than to a normal shape characteristic.
c. Lip closure
At rest, the lips should be able to meet without significant contraction of the chin or the perioral region.
The interlabial gap corresponds to the vertical space remaining between the two lips when the jaw is in the rest position.
With lips naturally joined:
interlabial gap ≈ 0 mm
Persistent separation can greatly alter the appearance of the mouth and often depends on the position of the incisors, jaws, facial height or soft tissues rather than the lips alone.
7. Lips seen in profile
a. Upper and lower lip projection
In profile, we must distinguish the thickness of the vermillion from its projection.
A lip can be thick vertically without protruding much forward, or on the contrary be quite thin but projected by the position of the teeth and the maxilla.
The upper lip usually lies slightly forward of the lower lip when the face is viewed from a vertical perspective.
However, the lower lip is usually closer to the E-line, as this line slopes between the nose and chin.
Balance therefore depends less on the fact that one lip “exceeds” the other than on their relationship with the nose, incisors and chin.
b. E-line
The Ricketts E-line is one of the simplest methods for measuring labial projection.
On a strict profile, we draw a line between:
tip of the nose, or pronasal → most advanced point of the chin, or pogonion
We then measure perpendicularly the distance between this line and the most advanced point of each lip.
A negative value means the lip stays behind the line.
A positive value means it sticks out in front.
The classic reference gives approximately:
upper lip: −4 mm
lower lip: −2 mm
The lower lip is therefore slightly closer to the E-line than the upper.
Modern preferences, however, allow for more projection than older orthodontic standards. In an experiment using an idealized white male profile, the highest-scoring positions when the lips were moved together were around 4 to 6 mm behind the E-line, while strong retrusion or moving in front of the line decreased attractiveness.
The E-line is highly dependent on the size of the nose and the projection of the chin. It should therefore be considered as a measure of profile balance, not as an isolated measurement of the lips.
c. Nasolabial angle
The nasolabial angle describes the transition between the nose and the upper lip.
On a profile, it is measured at the subnasal level between a line following the columella and a line following the upper part of the lip:
columella → subnasal → upper lip
A shallow angle produces a more closed transition. A high angle gives a more open transition and generally makes the upper lip appear more pulled back.
In humans, several studies have found preferences around 90 to 100°.
A classic study found around 96° in men. Another found around 97°. A 3D study published in 2025 found 90° as the best rated male angle among 70°, 80°, 90°, 100° and 110°.
A zone around 90 to 100° therefore constitutes a good male benchmark, with around 95° as a practical central value.
d. Mentolabial angle
The mentolabial angle measures the transition between the lower lip and the chin.
It is formed around the mentolabial fold, between the lower surface of the lip and the anterior part of the chin.
A very narrow angle produces a deep and marked furrow. A very open angle further erases the separation between lip and chin.
A study using an idealized Caucasian male profile found the most attractive zone to be approximately 107 to 118°.
This measurement strongly depends on the projection of the chin and lower incisors, but it directly participates in the integration of the lower lip into the profile.
8. The general shape sought
a. From the front
The mouth is sufficiently wide in relation to the nose and jaw.
A mouth/nose ratio around 1.5 to 1.6 and a mouth/bigonial width ratio around 0.40 to 0.48 constitute good benchmarks.
The lower lip is generally higher than the upper, with a lower/upper ratio around 1.5 to 2. A ratio close to 1.6 to 1.9 works particularly well for a male body shape.
Cupid's bow remains visible without being extremely narrow. Its width represents approximately 28% of the width of the mouth in a large sample of male models and its central angle is around 138°.
The corners are straight or slightly raised and the entire mouth remains close to horizontal.
b. Vertically
The philtrum remains sufficiently short compared to the rest of the lower third.
A length around 2.5 to 3 times the height of the upper vermillion is a useful benchmark.
Between the base of the nose and the chin, the mouth-chin distance is approximately twice the nose-mouth distance.
The lips thus occupy a relatively high position in the lower third without coming excessively close to the nose.
c. In profile
The lips have sufficient projection but remain integrated between the nose and the chin.
The upper lip retains visible support and the lower lip does not protrude strongly forward of the entire profile.
Compared to the E-line, a slightly recessed position remains a good benchmark, traditionally around −4 mm for the upper lip and −2 mm for the lower lip.
The nasolabial angle is approximately between 90 and 100° and the mentolabial angle is around 107 to 118°.
9. The main measures
a. Lower lip/upper lip ratio
Measurement: stomion height → labial inferius ÷ labial superius height → stomion
Benchmark: approximately 1.5 to 2
Central value: approximately 1.6 to 1.9
b. Total height of vermilion in relation to width
Measurement: labial superius height → labial inferius ÷ left cheilion width → right cheilion
Benchmark: approximately 0.33 to 0.40
c. Mouth-to-Nose Ratio
Measurement: left cheilion width → right cheilion ÷ left alare width → right alare
Benchmark: approximately 1.45 to 1.65
Central value: approximately 1.5 to 1.6
d. Mouth-to-Bigonial Ratio
Measurement: left cheilion width → right cheilion ÷ left gonion width → right gonion
Benchmark: approximately 0.40 to 0.48
Central value: approximately 0.42 to 0.45
e. Philtrum / upper lip
Measurement: subnasal height → labial superius ÷ labial superius height → stomion
Benchmark: approximately 2.5 to 3
Central value: approximately 2.7
f. Width of Cupid's Bow
Measurement: left crista philtri width → right crista philtri width ÷ left cheilion width → right cheilion
Benchmark: approximately 0.28
g. Cupid's Bow Angle
Measurement: left crista philtri angle → labial superius → right crista philtri
Benchmark: approximately 130 to 145°
Central value: approximately 138°
h. Vertical mouth position
Measurement: stomion distance → chin ÷ subnasal distance → stomion
Benchmark: approximately 2
The distance under the mouth is therefore approximately twice that between the nose and the mouth.
i. Chin-to-Philtrum Ratio
Measurement: labial inferius distance → chin ÷ subnasal distance → labial superius
Benchmark used: approximately 2 to 2.5
Some classifications extend the range to around 2.75.
j. General inclination of the mouth
Measurement: angle of the left cheilion → right cheilion line relative to the horizontal
Benchmark: close to 0°
Value observed in attractive male models: approximately 1°
k. E-line — upper lip
Measurement: perpendicular distance between the most advanced point of the upper lip and the pronasal line → pogonion
Classic benchmark: approximately −4 mm
A negative value means the lip is behind the E-line.
l. E-line — lower lip
Measurement: perpendicular distance between the most advanced point of the lower lip and the pronasal line → pogonion
Classic benchmark: approximately −2 mm
mr. Nasolabial angle
Measurement: columella angle → subnasal → upper lip
Male benchmark: approximately 90 to 100°
Central value: approximately 95°
n. Mentolabial angle
Measurement: angle formed between the lower lip, the bottom of the mentolabial fold and the anterior contour of the chin
Benchmark: approximately 107 to 118°
10. The most useful measures
To quickly describe the lips, the most informative measurements are the ratio of the two vermilion, the width of the mouth in relation to the nose and jaw, the length of the philtrum, the vertical position of the mouth and the projection of the lips in profile.
A set close to:
lower/upper lip: 1.6 to 1.9
mouth/nose: 1.5 to 1.6
mouth / bigonial width: 0.42 to 0.45
philtrum / upper vermilion: approximately 2.5 to 3
Cupid's bow: approximately 130 to 145°
mouth-chin / nose-mouth: approximately 2
E-line: slightly recessed lips
nasolabial angle: approximately 90 to 100°
mentolabial angle: approximately 107 to 118°
describes fairly large male lips, present without being excessively thick, with a more developed lower lip, a proportionate philtrum and good integration in the lower third and profile.
