34C

34C is a bra size commonly used in US sizing. It indicates a band size around 34 inches and a C cup. The exact volume of the C cup can vary by brand and style, so two bras labeled 34C may feel different from one brand to another.

How it is determined: In standard US sizing, the band size is determined by measuring around the torso directly under the bust and choosing an even number close to that measurement. The cup size is determined by the difference between the bust measurement (around the fullest part of the chest) and the band measurement. Each inch of difference typically corresponds to a cup letter, with about 3 inches difference often equating to a C cup. Because cup volumes differ by brand and cut, the same numeric size can fit differently across manufacturers.

Measuring method: Use a soft measuring tape. Stand straight and measure under the bust to determine the band size, rounding to the nearest even number. Then measure around the fullest part of the bust to find the bust measurement. Subtract the band measurement from the bust measurement to estimate the cup size (1 inch = A, 2 inches = B, 3 inches = C, etc.). Try on multiple styles, as padding, support, and shape influence fit.

Sister sizes and regional notes: Sister sizes for 34C include 32D and 36B (same cup volume with different band sizes). Bra sizing varies by region and brand, so it’s common to try bras in neighboring sizes or different brands to find the best fit.