According to multiple scientific studies and surveys, the proportion of men who have sexual interest in feet (foot fetish or foot-related fantasies) is approximately 10% to 20%. The most reliable data comes from a large survey conducted by American sex psychologist Justin Lehmiller involving over 4,000 people: about 18% of heterosexual men have had noticeable sexual fantasies involving feet or toes. The proportion is higher among gay or bisexual men, around 21%.

The proportion of women who have a sexual interest in feet (foot fetishism or foot fantasies) is significantly lower than that of men, about 5% to 11%, compared to 18% and 21% of men. The most reliable data is still from Justin Lehmiller's large survey (4,000+ Americans): Heterosexual women: about 5% have had explicit sexual fantasies involving feet or toes.
Lesbian or bisexual women: about 11%.
This compares to 18% for heterosexual men and 21% for gay/bisexual men.

Other studies support similar conclusions: some surveys show that the overall proportion of women's foot fantasies is around 4%~8% (e.g., 17% of men and 4% of women in one study; the other was 19% for men and 6% for women).
A small study in Belgium found that the proportion of women in foot fetishism was about 4.1%.
In general, foot fetishism (especially strong fetishes) is far less common in women than in men, with a proportion of about 1/3~1/4 of men.

It is necessary to distinguish: the proportion of "having had sexual fantasies about feet" is higher, but the proportion of "real foot fetish" (feet are the main or necessary source of sexual arousal) is lower among women, which may only be 1%~5%.
Female sexual fantasies tend to be emotional, romantic, or multi-partner scenarios rather than body-specific fetishes; Foot fetishism ranks low among common fetish types for women.

An analysis by the University of Bologna, Italy, in 2006 showed that foot fetishism is the most common type of fetish discussed online. Some surveys estimate that the general tendency for foot fetishism among men is around 10-15% or 16-17%.

It is important to distinguish between "having sexual fantasies involving feet" and "having a true foot fetish" (i.e., feet being the primary or necessary source of sexual arousal), with the latter being possibly lower, around 5-10%. Many men may simply mildly appreciate attractive feet without having a strong fetish.

Foot fetishism is primarily a male-dominated variation of sexual preference, which is significantly less present in women and mostly mild or occasional fantasies. Surveys fluctuated slightly due to differences in sample, culture, and definitions, but the gap between men and women was consistent (about 3 times that of women). This is a normal diversity and does not need to be considered an anomaly.
Overall, foot fetishism is one of the most common non-genital body part fetishes among men, far more prevalent than generally assumed, and is considered a normal variation of sexual preference, not abnormal. Different cultures and survey methods may cause slight variations in data, but around 18% is the most frequently cited figure.