How big does the penis have to be for the woman to achieve satisfaction?

Any size will do: Any size is fine. Other than babies with penis birth defects, pubertal boys with hormonal deficiencies, or rare cases of underdevelopment, treatment to enlarge one's penis is not necessary. For adult males, a penis with a firm erection is large enough if the penis touches the sides of the other person's opening, which is a vagina in the vast majority of cases.

Small can be better: A smaller penis may get harder, and since most of a woman's nerve endings are in the vulva (outer portion), a shorter one may provide better stimulation. Three inches is plenty. A woman's satisfaction has even more to do with the relationship and what else you can do with other parts of your body to stimulate her, show affection. Asks what she likes and make it your task to please her.