Prause et al. (2015) examined the preference for penis size in their male partners among women.

It found that, presented with scale 3D printed dildos, women preferred a penis of slightly larger circumference and length for one-time (length = 6.4 inches/16.3 cm, circumference = 5.0 inches/12.7 cm) versus long-term (length = 6.3 inches/16.0 cm, circumference = 4.8 inches/12.2 cm) sexual partners.

Somewhat expectedly, there was very little difference in preference between penis size for "one-time" sex vs "long-term" sex. After all, an ideal penis is preferable for any sex, regardless of the conditions of the sex. For practical purpose, only "one-time" sex preference will be used, because that is more applicable to low inhibition sex with the more explicit intention of pleasure.

Calcsd allows us to compare these statistics to composite datasets (https://calcsd.netlify.app/full):

Results from non-bone-pressed lengths (not pressing into the pubic fat pad, which is more practical to what women would assess), the dimensions are top 1.41% in length, top 19.16% in girth, and top 5.40% in total volume.

Additionally, 21% of the study's participants also admitted they had terminated a relationship, among other reasons, due to the partner's penis being "too small," compared to only 7% saying the same for a partner's penis that was "too big."

It is worth noting that the 7% of women claiming that a partner's penis was too big could overlap with the 36% indicating having experienced pain from intercourse. Generally speaking, a penis being "too big" is indicated by pain, which is something that even women with very little sexual experience can experience.

On the other hand, a penis being "too small" is arguably more dependent on a woman having a reference of a more ideal, larger penis. It could be argued that women with more sexual experience (possibly in conjunction with exposure to pornography, sex toys, etc.) would be more likely to report a penis being "too small" than those with less sexual experience.

Costa et al. (2012) found that women who preferred longer penises in their male partners were more likely to experience an orgasm from penis-in-vagina (PIV) intercourse, but there was no relation between preference for larger penises and their likelihood of experiencing a clitoral orgasm. It was also found that the women who were more likely to orgasm from longer penises were not more orgasmic overall, compared to the other women in the sample. Eisen (2001) reported that 90% of women agree that penis girth is more important than length for their sexual satisfaction.

References