I ordered the Small size with confidence as I'm a 29/30 waist, and I would say the fit is ideal there - not very tight at all, yet not loose either. The waistband is comfortable as is the material itself, but the short legs tend to ride up and bunch with movement.  However, this seems to be a common issue in the realm of tighter-fitting briefs. I assume most would share the same drawback, though perhaps a longer inseam would perform differently. I mostly wear loose fitting briefs, so I never gave much thought to it, but I suppose these have their place and are worth owning. I'm just glad I didn't buy a pair that cost 3x more to find out they bunch as well. For 9$, these are still plenty wearable, bunching issue notwithstanding.