Size Conversion Charts



Convert my Size

To simplify the often treacherous bra sizing, we have developed a unique sizing and measuring system. By finding your Phaein cup size you'll never get confused between band/cup size changes again.

If you already know your bra size you can easily check what it is in our system, using the chart below. Find your regular bra size, then follow the row to the right to find your Phaein cup size. Follow the coloumn to the bottom to find your Phaein band size.

Not sure about your size? Have a look at our easy measuring guide here.

Find your Phaein bra size chart


Find your Phaein cup size - and never get confused between band/cup size changes again! Each colour on the chart below shows you which cup sizes have the same fit. In traditional sizing, you need to go UP a cup size when you go DOWN a band size, if you want to keep the SAME CUP SIZE. This phenomenom is also called ‘Sister sizing’.

We find this unneccesarily confusing and created one cup size that remains consistent across bands - find yours by following the matching colour to the coloumn on the right.

Sister Sizes chart

 Why do our sizes look so weird?

To avoid confusion with 'normal' bra sizing we've re-labeled ours. We decided to write our size like this: bandsize.cupsize 

Cup sizes - Our current cup sizes range from 3-10 (see the charts above to find yours).
Band sizes - 60 - 80. Our band sizes use the European system to avoid confusion with American and British measuring systems, which sometimes do, sometimes don't, add 4 inches, but are all written the same (i.e 30, 32, 34 etc).


To ensure you get the best fit possible please take a minute to read our fit guide. Remember that all brands cut differently, and you may be a different size in different brands.

We're here to help. Contact us on or dm us on @phaein_official with any questions or feedback you have. We'd love to hear from you!