Bra Sister Sizes Explained

If your bra cups fit well but the band feels too tight or too loose, trying a sister size can help. Sister sizes have roughly the same cup volume and a different band length.

How to find a sister size

  • For a firmer band, go down one band size and up one cup size. From a UK 34D, try a 32DD.
  • For a roomier band, go up one band size and down one cup size. From a UK 34D, try a 36C.

Check the fit when you try it on

Start on the loosest hook with a new bra. The band should sit level and feel comfortably snug. The cups should sit smoothly without spilling or gaping. If the cups already feel too small or too large, try a different cup size or bra shape. Fit also varies by brand and style, so check the brand’s size chart when shopping online.

Browse bras, read our bra-care guide or visit us in Midhurst for a one-to-one fitting.

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