Breast size is unique to each woman and is determined by several factors, especially genetics, nutrition, weight, and age. An individual’s breast size can also vary at times, depending on a woman’s menstrual cycle and whether she is pregnant or nursing. Nonetheless, the average breast size in a country can be determined by looking at the average size of bras sold.
While there are different ways of measuring country to country, bra sizes are generally expressed by cup sizes. To determine cup size, fitters measure around the fullest part of the breast and compare that to the “underbust,” the measurement around the smallest part of the breast. The greater the difference between these measurements, the larger the cup size. These measurements are expressed in letters, from greater than D (known as “DD”) down to A cups, with variations within the cup sizes noted by levels ranging from 5 to 1 for each cup size. Accordingly, bra sizes range from DD-5 to the smallest size, A-1.
When it comes to breast size, four countries stand out. The Nordic countries of Finland, Norway, and Sweden, plus Russia, have the largest average breast sizes at DD-5. The United States is directly behind these countries, with an average breast size of DD-4. Overall, the largest breast sizes are concentrated in Europe and the United States, with several countries reporting DD and D sizes. The smallest breasts are concentrated in African and southeast Asian countries, with mostly B and A cups throughout those regions.