Bra Size Calculator
Calculate Bra Size
Enter your underbust and bust measurements in inches
in
in
Formula
Band = round underbust to nearest even number | Cup = bust − band (1"=A, 2"=B, 3"=C, 4"=D, 5"=DD)
Frequently Asked Questions
How do I measure my bra size?
Measure your underbust (ribcage directly under your breasts) and your bust (fullest part) with a soft tape measure. Keep the tape snug but not tight. Round the underbust to the nearest even number for your band size, and the difference between bust and band determines your cup size.
What is a sister size?
Sister sizes are bra sizes with the same cup volume but different band sizes. For example, 34C, 32D, and 36B all hold the same cup volume. Going up a band means going down a cup, and vice versa.
Do US and UK bra sizes differ?
Band sizes are the same in US and UK systems, but cup sizes diverge after D. US uses DD, DDD/F, G... while UK uses DD, E, F, FF, G, GG...