I was measured at my local outdoors store and they said I have a 17 inch torso and should wear a size small (but he asked me where my hips were and I pointed kind of generally). Whenever I try to measure myself, I end up with between 19 and 20 inches, which is a medium. Maybe I'm a little confused about where exactly I should measure on my hip bones. Do I want the pack hip belt to rest on top of my hip bones(with the bottom part matching up with the top of my iliac crst) or over my hip bones so that the padded belt cups my hip bones and my iliac crest is hidden beneath the padding?
Personally, I feel a lot more comfortable with the belt cupping around my hips rather than sitting on top, like most resources suggest. I feel like the pack rides up and is around my stomach this way. Maybe I'm just not used to having things gripping my waist, but I'm not sure what is right.