What is Filth Factor?
1.
An international version of the Scandinavian "Fultal", literally: "Ugly Number". Simply the amount of partners a person has slept with, multiplied by the difference in age between the youngest and oldest.
Ex. 15 partners, youngest born 1985, oldest 1975, filth factor of 150.
- Karen spent the night at that 65 year old's place.
- Oh my god, her filth factor must have gone through the roof!!
See