Average flaccid and erect penile length and girth. What would be called "big" for flaccid length, flaccid girth, erect length, erect girth?

1. What the large reviews report as average and how they measured it

A widely cited systematic review that pooled clinician‑measured data found mean flaccid length ≈9.16 cm, stretched ≈13.24 cm, erect ≈13.12 cm, with mean flaccid circumference ≈9.31 cm and erect circumference ≈11.66 cm; those length measures were taken bone‑to‑tip after compressing the pubic fat pad and girth measured at base or mid‑shaft ^{[1] [2]}; other meta‑analyses report similar but not identical figures—one systematic review found a mean erect length around 13.8 cm in a subset of 5,669 men—underscoring modest interstudy variation ^[6].

2. Why numbers vary: self‑report, technique and population effects

Studies that rely on self‑measurement systematically overestimate size compared with clinician‑measured data, and differences in whether fat pad compression or foreskin length is counted change results; population mix, age, obesity and even measurement temperature can affect flaccid dimensions and produce heterogeneity across studies, which is why clinician‑measured meta‑analyses are preferred for normative estimates ^{[1] [2] [7]}.

3. What people call “big”: statistical and social definitions

There is no single scientific cutoff for “big,” but two practical anchors appear in the literature: statistical outliers (top decile or more than ~1–2 standard deviations above the mean, often used in medical nomograms) and lay or partner preferences—several preference studies show idealized choices around 16.0 cm (6.3 in) length and ~12.2 cm (4.8 in) girth for long‑term partners, figures that functionally act as a social definition of “large” in some surveys ^{[8] [3] [4] [5]}.

4. Clinical extremes and medical definitions

Medicine uses the term “micropenis” for clinically small extremes—commonly defined as an erect length under roughly 7.5 cm (3 in) or a flaccid length near 4 cm at birth—showing that clinical thresholds focus on functional and developmental concerns rather than colloquial size judgments ^[9].

5. Trends, context and commercial incentives

Meta‑analyses suggest erect length estimates have increased over recent decades—one systematic review observed a significant temporal increase of about 24% across certain regions from 1992–2021—yet measurement heterogeneity and potential sampling biases complicate interpretation ^[10]; meanwhile, clinics and device vendors who promote augmentation or implants have an incentive to emphasize dissatisfaction and larger “ideal” sizes, so their messaging should be weighed against clinician‑measured nomograms and peer‑reviewed meta‑analyses ^{[8] [11]}.

6. Practical takeaways and limits of the evidence

For practical comparison, the best current clinician‑measured averages are flaccid ≈9.16 cm (3.6 in) and erect ≈13.12 cm (5.16 in) with girths ≈9.31 cm (3.67 in) flaccid and ≈11.66 cm (4.59 in) erect ^{[1] [2]}; “big” is context‑dependent but commonly used social benchmarks—around 16 cm erect and 12 cm girth—are supported by preference studies, while medical concern centers on the low extreme (micropenis) rather than high values ^{[3] [4] [5] [9]}.