I'm sized to fit in the medium (Abu) but I know some diapers fit bigger than others and I comfortably wear small rearz over the mediums as there's a size overlap and the smalls I find fit better. Now I've never tried Abu diapers and not sure if the smalls will be too small as there isn't a size overlap typically a 30-32" waist in jeans. Mediums the top tapes almost touch on first application