A bra calculator can be used to help determine bra size. The big caveat is that most bra calculators are absolute garbage; they're so bad as to be completely useless.

How to tell if a calculator is inaccurate

Signs of a bad bra calculator include:

  • If it tells you to measure your "overbust", or under your armpits
  • If, in UK and US calculators, the band size is several numbers larger that the number you put as your ribcage or underbust measurement (ex: Your ribcage measures 38 but the calculator tells you to wear a 42)
  • If, in EU/JP calculators, it says the number you measured your ribcage as is the same as your band size (ex: your ribcage measures 65cm, and the calculator says to wear a 65). The EU/JP sizing system has "plus four" built into it

Bra fit calculators

There are a few fit calculators that yield accurate results.[1]

See also


  1. Butterfly Collection: "Bra Sizing Calculators"
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