Bra sizing is determined by the numerical difference between the ribcage (band) and the fullest part of the bust.

: Specializes in "tween" and petite adult sizes with a focus on comfortable, wire-free options. AI responses may include mistakes. Learn more Little Women Bras for Small Busts | AAA AA & A Cup Bras

: For context, an AA cup typically measures a 0.5-inch difference, while a standard A cup represents a 1-inch difference. Why the AAA Size Matters

: Generally indicates that the bust measurement is less than 0.5 inches larger than the band size.