Understanding C Cup Bra Size: Measurements & Fit Guide

C Cup Bra Size: What It Means

A C cup indicates a 3-inch (7.5 cm) difference between bust circumference (fullest part) and underbust (band) measurement.

How Bra Sizing Works

• Band size: Underbust measurement (rounded to even number: 32, 34, 36...)
• Cup size: Difference between bust and band:
  • A = 1" difference
  • B = 2" difference
  • C = 3" difference
  • D = 4" difference
  • DD/E = 5" difference

Examples

Band	Underbust	Bust (C Cup)	Difference
32C	~32" (81 cm)	~35" (89 cm)	3"
34C	~34" (86 cm)	~37" (94 cm)	3"
36C	~36" (91 cm)	~39" (99 cm)	3"
38C	~38" (97 cm)	~41" (104 cm)	3"

Important Considerations

• Sister sizes: 34C = 32D = 36B (same cup volume, different band)
• Brand variation: Sizing differs between manufacturers — always try on
• Shape matters: Fullness distribution (top/bottom/center) affects fit beyond size
• Professional fitting recommended for best results

Cup size is relative to band size—a 32C has smaller cups than a 38C despite both being "C cup."