knowhersize

Bra Sizing Basics: How Sizes Work, Measuring and Converting

Every bra size is two facts: a band from the snug measurement under the bust, and a cup that counts the inches between that and the fullest part. These guides explain the system, show you how to measure in a minute, and translate a size between the US, UK, Australia and Europe.

Understand bra sizes

Cup letters

Measure

Convert between countries

Get the size in about a minute

Measure with a tape, read a bra tag, or start from a clothes size. You get the size in US, UK, AU and EU sizing, with sister sizes. Free, and nothing leaves your phone.

Open the bra size calculator

Buying a gift? Keep her sizes together on her size card.