1. Take a snug measurement of the fullest part of your chest using a tape measure (best if measured while clothed) and write that number down onto a sheet of paper.
2. Measure underneath your chest where the crease is and write that number down as well.
3. Add those numbers together and divide the sum by 2. This number will differentiate your size not only from brand to brand but from binder to binder as well.
(from: https://www.genderconfirmation.com/breast-binding/ )
Note: Every binder company/website has their own size chart for the binders they sell. I'd recommend following their measurement guides!
YOU ARE READING
Binding: Maxwell's Guide
Non-FictionA Guide to Binding complied by Maxwell Xander (None of the images belong to me; credit to owners)