A pair of pants I like to hike in are 29" inseam. When I measure my body, it's more like 27.5" - 28.5" (I'm not great at measuring hehehe). I'm 39" from my natural waist to the floor (I marked the wall next to my natural waist above my hips, then measured from that mark on wall to the floor.)
I had my roommate measure my back following the REI video instructions, and I come out to 16.5" - 17". I'm about 29-30" circumference there (waist is 26", about 2.5-3" above REI measurement location) so it's a higher measurement point than the Zpacks instructions. I'm rockin' a decent amount of fat right now, so it makes measuring iliac crest tricker than when I'm thin.
I'm really not sure if this pack will work or not, but decided to risk it. There is the Scout on their website that I was also considering. I can always sell this one if need be. My two previous packs are a 2009 Gregory Women's Jade 50 size XS and a 2017 Gossamer Gear Gorilla size Small, Hipbelt Small.
That Gossamer Gear hipbelt was way too small! Their website says, "Small hip belt (24" - 34" waist) (61 - 81 cm)" My waist ranges from 24.5 - 26.5." No where close to the maximum end of their waist range. My hips are 34.5 - 36.5" I didn't realize it was men's sizing, since it didn't say the Gorilla was a man's pack. Won't shop there again, that's for sure! (Missing stitching didn't help my opinion of them either..) Two years later I'm still pissed off... and two years later they still have men's sizing in a supposed unisex pack. OK /end rant
I'll follow up here once I get the Zpacks backpack, and let you know how it fits me.