What is the average penis size preferred by women in their 20s?

1. How the most-cited academic study measured preference — and what it actually found

A controlled laboratory study used 3D‑printed, lifelike penis models and asked sexually experienced women to choose preferred sizes for short‑term and long‑term partners; results showed women preferred an erect length of 6.4 inches and girth of 5.0 inches for one‑time partners, and 6.3 inches length and 4.8 inches girth for long‑term partners — described by the authors as “only slightly larger than the average” ^[1]. The paper emphasizes the small difference between preferred size and measured averages and reports women recalled model sizes reliably ^{[5] [1]}.

2. What “average” erect size means in medical literature

Medical reviews collating multiple measurement studies place typical erect length around 5.1–5.5 inches (about 12.9–13.9 cm), with girth estimates near 4.6–4.9 inches; these averages come from pooled and physician‑measured studies and are cited by health outlets summarizing the literature ^{[2] [3]}. The academic preferred sizes above therefore sit roughly 1.0–1.3 inches longer than those averages ^{[1] [2]}.

3. Why different studies and polls produce different “ideal” numbers

Methodology drives variation. The academic 3D‑model study used tactile, standardized stimuli and a modest, demographically limited sample (mostly California residents) ^{[5] [1]}. Other reports — including media summaries, private surveys, and clinic marketing — use online polls, larger but self‑selected samples, or commercial scales; these can return lower (e.g., 5.5 inches) or higher (e.g., reports claiming 7+ inches) preferred sizes depending on question framing and the vendor’s agenda ^{[3] [4]}. Sources such as Moorgate Andrology published headline‑grabbing claims (7.5 inches) tied to promoting procedures, which signals a potential commercial motive ^[4].

4. What women say about importance, beyond raw inches

Multiple sources report most women place limited emphasis on size relative to technique, intimacy, and partner responsiveness; many surveys find a large majority satisfied with their partners’ size and that girth can matter as much as length ^{[6] [7] [8]}. The 3D‑model research itself frames preferred sizes as only slightly above average and notes that relationship context (one‑time vs. long‑term) influences choices ^{[1] [5]}.

5. Limitations and gaps in reporting you should know

Available sources show variation by sample, measurement method and commercial interest: the 3D study sample was not nationally representative and other surveys rely on self‑report or clinic promotion ^{[5] [4]}. Medical reviews caution that “average” estimates vary with measurement technique and that men tend to misreport size, complicating comparisons ^{[2] [8]}. Available sources do not mention a definitive, nationally representative survey of women in their 20s alone reporting a unique “average preferred” figure specific to that age group — age‑segmented preference data are not found in current reporting (not found in current reporting).

6. How to interpret the numbers practically

Treat the commonly cited figures — ~6.3–6.4 inches preferred and ~5.1–5.5 inches average erect — as approximations shaped by study method ^{[1] [2]}. The strongest evidence (3D models) shows preference only modestly above average and context‑dependent; commercial claims that prime preference is much larger should be weighed against likely marketing incentives ^[4]. Multiple sources emphasize sexual satisfaction depends far more on communication, technique and compatibility than a single measurement ^{[6] [3]}.

Sources cited: Prause et al. 3D‑model study and PubMed summary ^{[5] [1]}; Medical News Today review of average size ^[2]; Ro and Hims writeups and media summaries ^{[6] [9] [3]}; Moorgate/clinic coverage signaling commercial motives ^[4]; contextual summaries on satisfaction and averages ^{[7] [8]}.