Specimen No. 066 · Terrestrial Mammal
Domestic Horse / Stallion penis size & anatomy
Equus caballus
Reference measurement
Approx. 1 m / 3.3 ft
Approximate erect penis length
University of Kentucky equine reproduction material reports the non-erect stallion penis at about 50 cm and states that it approximately doubles in length and thickness during erection. For comparison purposes, 100 cm is used as an approximate erect length. This is a derived estimate, not a published 100–100 cm measurement range.
Measurement source: University of Kentucky — Stallion Reproductive Anatomy (opens in a new tab)
Did you know?
Talk about a grower: a stallion's penis is approximately 50 cm (19.7 in) long when non-erect and can roughly double in length during erection, reaching around 1 meter (39.4 in).
Source: University of Kentucky — Stallion Reproductive Anatomy (opens in a new tab)
Unlike the dromedary camel's fibroelastic penis, the stallion has a musculocavernous penis. Erection involves substantial blood engorgement, producing a dramatic increase in both length and diameter.
Source: University of Kentucky — Stallion Reproductive Anatomy (opens in a new tab)
The stallion's glans expands substantially during erection. Its corona glandis forms the prominent rim around the head of the penis.
Source: University of Kentucky — Stallion Reproductive Anatomy (opens in a new tab)