How to Measure Your Boobs

Apparently, around 80% of people don’t know their correct bra size (meaning that they’re living in permanent discomfort from an ill-fitting bra!) Crazy isn’t it?! Let’s sort that out. 

Finding Your Size

Your bra size is measured by your band size (which is the number) and your cup size (which is the letter). Follow our simple steps to getting your correct measurements.

  • Take off your bra, grab a flexible tape measure and be sure to measure in inches.
  • Begin with the band. Take the tape around the rib cage, directly under the bust and completely level (you should be able to get roughly two fingers under the back).
  • This measurement is your band size - but some brands vary in their measurements so always double check.
band measurement


  • Now to the bust. Take a loose measurement over the fullest part of the bust, keeping the tape completely level around the body. Tip: take a deep breath in and out to make sure that the tape isn’t too tight.
  • Using these measurements, you can now calculate your bra size.
bust measurement


  • Use our conversion table below to help understand your cup size. 
  • Remember: sizing can vary from brand to brand and it is always important to try on bras to find the best fit.
bust to cup conversions

Sister Sizes

Simply put, sister sizes are used when you can’t find the bra you want in the right size. It’s important to mention that they aren’t the same as wearing a bra that fits like a glove, but they are handy to keep in mind if you’ve set your heart on a good bra.

sister size bras

The rule: if you go up one band size, go down one cup size. And vice-versa, if you go down one band size, go up one cup size.

Head over to our guide on how your bra should fit to find out how to use your size measurements to find the right bra. 

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