What is the difference in the number of ribs between women and men?

Number of Ribs in Women vs Men

Both women and men have exactly 12 pairs of ribs (24 total ribs), with no difference in rib number between the sexes. 1

Anatomical Structure

The rib cage consists of a standardized skeletal framework that is identical in number across both sexes:

• Ribs 1-7 are classified as "true ribs" because their costal cartilage directly articulates with the manubrium and sternum 1
• Ribs 8-10 are "false ribs" as their costal cartilage connects to the cartilage of the immediately superior rib rather than directly to the sternum 1
• Ribs 11-12 are "floating ribs" with rudimentary cartilage caps and no attachment to the sternum 1

Sex Differences in Rib Morphology (Not Number)

While the number of ribs is identical, there are important morphological differences between male and female rib cages:

• Shape and size variations exist between males and females at all ages, with statistically significant differences in rib geometry, location, and orientation 2
• Rib cage dimensions differ between sexes, with the shape being significantly affected by sex (p=0.0002), though this reflects structural differences rather than numerical differences 3

Clinical Relevance

The misconception about different rib numbers between sexes has no anatomical basis. However, sex-specific differences in rib cage morphology do have clinical implications:

• Fracture patterns may differ between sexes due to morphological variations rather than numerical differences 4, 2
• Biomechanical responses to thoracic trauma vary by sex due to structural differences in rib orientation and chest wall geometry 2