The philtrum is the vertical groove running from the base of the nose (subnasale) to the peak of the upper lip's vermilion border (labiale superius); "philtrum length" or "philtral height" is that distance in millimetres. In young adults it typically measures around 14–16 mm, runs roughly 1–2 mm longer in men than in women, and lengthens by several millimetres over adult life as the upper lip elongates and the visible vermilion thins.
It matters in facial analysis for two reasons: it is one of the few soft-tissue lengths that changes predictably with age, and it is the target of a common cosmetic operation, the lip lift. It is also routinely quoted to a false precision — an "ideal" of 11–13 mm circulates widely with no primary source we could verify.
Part of the SoftMaxx facial anatomy glossary — every term, one definition each.
1. What is being measured
Anthropometrists measure the philtrum from subnasale — the point where the nasal columella meets the upper lip — to labiale superius, the midline peak of the upper vermilion border. Two things are deliberately excluded: the red lip itself (vermilion height is a separate measure), and the two philtral ridges, whose prominence is a matter of relief, not length.
Method matters more than most people expect. Direct caliper measurement on the skin surface and landmark measurement from photographs give different values for the same face, and the lip-lift literature has been criticised for exactly this: a 2023 systematic review of nine studies found "a lack of consistency in the measurements used" across two incompatible families of technique (Zhao and colleagues, 2023, Aesthetic Plastic Surgery). When you compare your number to a published one, check how theirs was taken.
2. The normal range, by sex
Two recent direct-measurement studies agree closely. In a Lebanese young-adult sample, mean philtral height was 15.7 ± 1.7 mm in men and 14.3 ± 1.9 mm in women, a mean difference of 1.3 mm (Sleilati, Daou and Nassar, 2024, JPRAS Open). In 100 Indonesian adults aged 20–35 pre-screened as attractive, the figures were 15.85 ± 2.67 mm in men and 13.86 ± 2.32 mm in women (Hasibuan and colleagues, 2024, JPRAS Open).
Read the standard deviations, not just the means: roughly two millimetres either way at every age means a 12 mm philtrum and an 18 mm philtrum can both be entirely ordinary. The sex difference is real and consistent, but at 1–2 mm it is smaller than the spread within either sex.
3. How it changes with age
The philtrum lengthens across adult life, and this is one of the better-documented soft-tissue changes in the face. Comparing young and older women by direct measurement, mean philtral height rose from 14.3 ± 1.9 mm to 19.8 ± 2.4 mm — a mean lengthening of 5.5 mm (Sleilati and Chalhoub, 2024, JPRAS). An earlier photomorphometric and MRI study of women aged 20–35 versus 65–80 found the same direction: significant lengthening of the upper lip, with "an increase of prolabium skin at the cost of a decreasing visible upper lip vermilion" — and, notably, no demonstrable loss of lip volume on MRI (Iblher and colleagues, 2008, JPRAS).
So the ageing pattern is not that the lip deflates; it is that the skin portion stretches downward and the red portion rolls under. That is why a long philtrum with a thin vermilion reads as older even when the lip is not actually thinner.
4. What the attractiveness research actually shows
The evidence does not support a target philtrum length. What it supports is a proportion. In a study of 176 subjects rated by 250 people, attractive perioral regions had a significantly higher ratio of upper-vermilion height to nose-to-mouth distance than unattractive ones, in both women (p < 0.001) and men (p < 0.05) (Penna and colleagues, 2015, JPRAS). In other words: more visible red lip relative to the skin above it.
A separate morph study of young women's lips found the most attractive configuration was a large increase in lip surface area, an upper-to-lower lip ratio of about 1:2, and a lip area equal to roughly 9.6% of the lower third of the face (Popenko and colleagues, 2017, JAMA Facial Plastic Surgery) — again, area and ratio, not philtral millimetres. A 15 mm philtrum above a full upper lip and a 15 mm philtrum above a thin one are scored very differently.
5. What the lip-lift literature targets
The subnasal ("bullhorn") lip lift shortens the philtrum by removing a strip of skin under the nose. The best current summary — a 2026 evidence review of seven studies covering 1,754 patients — reports philtral length reduced from 14.0–14.5 mm to 10.8–12.0 mm, vermilion height increased from 5.0–6.0 mm to 7.0–9.0 mm, and upper-incisor show increased from 1.5–2.0 mm to 3.5–5.0 mm, with revision rates of 0.6–6.7% (Komisarek and colleagues, 2026, Journal of Cosmetic Dermatology).
Two things follow. First, the patients in those series started with philtrums around 14 mm — inside the normal young-adult range above — so the operation is usually performed on ordinary anatomy for aesthetic preference, not to correct an abnormality. Second, the popular "ideal 11–13 mm" figure is attributed online to a 2014 paper on the endonasal lip lift (Raphael, Harris and Harris, Aesthetic Surgery Journal); the paper is real, but its abstract contains no such figure and we could not verify it in the full text. The verified post-operative range, 10.8–12.0 mm, is the honest substitute. We describe the operation here; we do not advise on it — that is a conversation for a qualified surgeon.
6. What philtrum length does not tell you
- Whether the lip is attractive. Attractiveness tracked the vermilion-to-philtrum ratio (Penna 2015) and lip area and upper:lower ratio (Popenko 2017), not philtral length alone.
- A population-free "normal". Verified young-adult means already span 13.9–15.9 mm across two populations measured two ways, and outcome studies cannot agree on how to measure the philtrum at all (Zhao 2023). Any ideal quoted to the millimetre is false precision.
- Your age, or whether a short philtrum is natural. Lengthening with age is real (about 5.5 mm across adult life in women), but with ~2 mm standard deviations at every age a young person can measure 18 mm and an older person 15 mm.
- Anything about the philtral ridges. Their definition is a separate, largely unstudied variable.
Related measurements: facial thirds and fifths, gonial angle. How SoftMaxx measures the lower face is on the methodology page.
7. Sources
- Sleilati FH, Daou B, Nassar A (2024). Quantifying upper lip height difference between two young male and female populations by direct surface measurement. JPRAS Open. doi:10.1016/j.jpra.2024.07.022
- Hasibuan LY, Prasetyo AT, Pramono GNTW (2024). Comprehensive anthropometric lip measurements in youthful and attractive Indonesian adults. JPRAS Open. doi:10.1016/j.jpra.2023.12.014
- Sleilati F, Chalhoub R (2024). Quantifying female upper lip lengthening with age by direct surface measurement. J Plast Reconstr Aesthet Surg. doi:10.1016/j.bjps.2024.04.025
- Iblher N et al. (2008). Changes in the aging upper lip — a photomorphometric and MRI-based study. J Plast Reconstr Aesthet Surg 61(10):1170–6. doi:10.1016/j.bjps.2008.06.001
- Penna V et al. (2015). The attractive lip: a photomorphometric analysis. J Plast Reconstr Aesthet Surg 68(7):920–9. doi:10.1016/j.bjps.2015.03.013
- Popenko NA et al. (2017). A quantitative approach to determining the ideal female lip aesthetic. JAMA Facial Plast Surg 19(4):261–7. doi:10.1001/jamafacial.2016.2049
- Komisarek O et al. (2026). The Bullhorn and Beyond: evidence-based review of lip lift techniques. J Cosmet Dermatol. doi:10.1111/jocd.70703
- Zhao H et al. (2023). Different techniques and quantitative measurements in upper lip lift: a systematic review. Aesthetic Plast Surg. doi:10.1007/s00266-023-03302-5
8. Common questions
What is a normal philtrum length?
In young adults, roughly 14–16 mm measured from the base of the nose to the peak of the upper lip, with men about 1–2 mm longer than women and a standard deviation of about 2 mm at any age.
Is a long philtrum unattractive?
Not by itself. Attractiveness studies track the proportion of visible red lip to the skin above it, and lip area and ratio — not philtrum length alone. A longer philtrum with a full vermilion can rate well.
Does the philtrum get longer with age?
Yes. Direct measurements in women show a mean lengthening of about 5.5 mm between young adulthood and older age, as upper-lip skin stretches and visible vermilion thins.
What is the ideal philtrum length?
No verified primary source establishes one. The widely quoted 11–13 mm figure could not be traced to the paper it is attributed to. The lip-lift literature reports post-operative philtrums of about 10.8–12.0 mm, down from around 14 mm.
Can you measure philtrum length from a photo?
Approximately, if the photo is a true frontal view with a scale reference; head pitch and lens distance change the apparent length, and photographic and caliper methods give different values.