It is important for reasons of health, comfort and appearance to wear a bra that is the correct size for you. There are certain basic measuring guidelines, but these are only ever a guide as we all differ a little in bone structure.
Explicit chart (click to enlarge)
Measure the chest immediately underneath the bust, keeping the tape as tight as possible. This is the Underbust measurement, which gives you the correct back size.
Next, measure over the fullest part of the bust (not so tightly this time), which will give you chest+breast measurement resulting in the overbust measurement, this gives you your cup size.
You’ll find on the right, an explicit chart.
Warning, all measurements are done in centimeters. It gives you your french size.
If you already know own size in your country, or if you need a conversion because of size using by designers, you’ll find below a lot of conversion chart.
This size is generally well known. You’ll find below a conversion chart to help you to select it into the size requested on each product page (french/UK or US depending of product).
In case of doubt, please, refer to the explicit chart. Measurements are in centimeters and give you your french size.