It is important that the bra you are wearing is supportive and comfortable; there are a few areas which needs to be checked to make sure that everything is fitting correctly:


You need to be aware that one breast is usually slightly bigger than the other, for fitting always fit to the larger breast. The breast should be fully enclosed in the cup and should not:

  • Spill over at neckline
  • Bulge out at sides
  • Have a lot of excess fabric in the cup


The band should hold you firmly around, sitting nice and straight across your back. The band should not:

  • Arch up your back
  • Dig in or be too tight


The straps should sit comfortably on your shoulders; the straps should not:

  • Slip off your shoulders after adjustments have been made

  • Dig into your shoulders

Sister sizes

The sister sizing system is used if after you have measured you bra size; you are finding it is not the correct fit for your body shape. If the band is too tight; then you can go up a band size and go down a cup size. If the band is too loose; then you can go down a band size and go up a cup size.

Sister sizes all have the same cup volume but band and cup sizes are different. It can be confusing at first but understanding this can be very helpful. For example, if you have been wearing 34F and you start to feel it is tight on the band – then look for 34F in the chart and move one space to the right and you should then try wearing 36E. If the 34F band has become too loose, then look for 34F on the chart and move one space to the left and you should be wearing 32FF. The chart below shows the different sister sizes, each row of sizes are related: