Researchers compared the average volume and cup size of 400,000 women from 108 different countries to come up with their results.
They excluded women with breast implants, those who were pregnant, breastfeeding or had been pregnant in the past 12 months.
Lead researchers have explained their findings in the study, which was published in The Journal of Female Health Sciences.
Countries where women have biggest breasts
6. The Netherlands
12. New Zealand