A penis has three main visible parts: the shaft, the head (called the glans), and a small opening at the tip where urine and semen exit. Beyond that basic structure, penises vary widely in size, color, shape, and skin texture. What’s considered “normal” covers a broad range, and most of the differences people notice are completely harmless.
Basic External Anatomy
The shaft is the longest part of the penis, extending from the body to the tip. It’s cylindrical and somewhat soft when not erect, with skin that moves loosely over the tissue underneath. At the end of the shaft sits the glans, a rounded, slightly bulging head that’s typically smoother than the shaft. Where the glans meets the shaft, there’s a small ridge called the corona that circles the base of the head.
At the very tip of the glans is a tiny opening called the meatus. This is where urine and semen leave the body. On the underside of the glans, a thin strip of skin called the frenulum connects the head to the shaft, similar to the small fold of tissue under the tongue.
Circumcised vs. Uncircumcised
One of the most obvious visual differences between penises is whether or not the foreskin is present. The foreskin (also called the prepuce) is a retractable hood of skin that covers the glans. In an uncircumcised penis, this skin partially or fully covers the head when the penis is soft, and it slides back during an erection or can be pulled back manually. In a circumcised penis, the foreskin has been surgically removed, leaving the glans permanently exposed.
An uncircumcised penis often looks slightly more tapered or covered at the tip when flaccid, while a circumcised penis shows the glans and corona more prominently. Both are completely normal, and the overall shape and function remain the same.
Color, Skin, and Veins
Most penises are roughly the same color as the rest of the person’s skin, but many are noticeably darker, with a brownish or reddish tone. It’s also possible for the penis to be lighter than surrounding skin. These color differences are normal and have to do with how pigment distributes in genital skin, which is thinner than skin elsewhere on the body.
Veins are commonly visible along the shaft and may even bulge slightly, especially during arousal when blood flow increases. Dark spots can also appear on the skin and are usually harmless pigmentation changes. During arousal, the entire penis may temporarily look darker because of increased blood filling the tissue.
Normal Bumps and Texture
Small bumps on or around the penis are extremely common and almost always harmless. Pearly penile papules are tiny rounded or finger-like growths that appear in rows along the corona, the ridge where the glans meets the shaft. They look like white, yellow, or pink dots, each about 1 to 2 millimeters wide, roughly the size of a grain of rice. They’re more noticeable on the top side of the penis and are not contagious or caused by any infection.
Fordyce spots are another frequent finding. These are small, pale or yellowish bumps on the shaft or along the foreskin caused by oil glands that are visible through the thin genital skin. They’re present in most adults to some degree and are completely benign. Neither pearly penile papules nor Fordyce spots require treatment.
Size and Proportions
A large clinical review covering over 15,500 men found the average flaccid penis length is about 9.2 cm (3.6 inches), with an average erect length of 13.1 cm (5.2 inches). Flaccid circumference averages about 9.3 cm (3.7 inches), increasing to roughly 11.7 cm (4.6 inches) when erect. These are averages with a wide range of normal on either side. Some penises appear significantly smaller when soft but grow substantially during erection (“growers”), while others stay closer to their erect size at all times (“showers”).
The ratio of the glans to the shaft also varies. In some men, the head is noticeably wider than the shaft; in others, the transition is more gradual. None of these proportional differences affect function.
Shape and Curvature
Perfectly straight erections are actually uncommon. A slight curve to the left, right, up, or down is typical, with normal curvature ranging from about 5 to 30 degrees. Even curves greater than 30 degrees don’t necessarily indicate a problem if they don’t cause pain or interfere with sex. Curvature that develops suddenly in adulthood, comes with pain, or makes intercourse difficult is a different situation and worth having evaluated.
The overall shape of the shaft also varies. Some penises are wider at the base and taper slightly toward the head. Others are more uniform in width, and some are slightly thicker in the middle. All of these shapes fall within the normal range.
How It Changes During Arousal
When aroused, arteries in the penis expand and blood fills two tubes of spongy tissue that run the length of the shaft. This makes the penis larger, stiffer, and causes it to angle outward or upward from the body. The skin tightens, veins become more prominent, and the glans may deepen in color. The erection angle varies by person and by age. Some erections point nearly straight up, others are roughly horizontal, and some angle slightly downward. All are normal.
The Scrotum
Just below the penis hangs the scrotum, a loose pouch of skin containing the testicles. Scrotal skin has a distinctly wrinkled, textured appearance with visible ridges called rugae. This wrinkling is functional: the scrotum contracts and pulls the testicles closer to the body in cold temperatures and relaxes in warmth, helping regulate the temperature the testicles need for sperm production.
Asymmetry is the norm. One testicle (usually the left) hangs slightly lower than the other, and the two sides of the scrotum may differ slightly in temperature. The skin of the scrotum is often darker than surrounding body skin, and it may be sparsely or densely covered in hair depending on the person.
Changes With Age
The appearance of the penis shifts gradually over a lifetime. During puberty, the penis and testicles begin increasing in size around age 11 to 12, and growth continues until roughly age 16 to 17. Pubic hair develops in stages alongside genital growth, starting sparse and fine and reaching adult density and distribution by the late teens.
In later adulthood, blood flow to the penis decreases over time, and erections may become less firm and less frequent. The skin of the shaft and scrotum may lose some elasticity, and pubic hair often thins and grays. Fat accumulation around the lower abdomen can also make the visible portion of the shaft appear shorter, even though the underlying structure hasn’t changed. Sensitivity in the glans gradually decreases with age as well.