Breast volume is affected by body mass index but not age.
Celeste E ColtmanJulie R SteeleDeirdre E McGheePublished in: Ergonomics (2017)
It is recommended that bra cups must be designed to support the wide range and increasing magnitude of breast volumes exhibited by women. Practitioner summary: This original research provides evidence for bra designers and manufacturers on the range of breast volumes of women and the significant effect of BMI on breast volume. Bra cups need to be designed to support the wide range and increasing magnitude of breast volumes exhibited by women.