Gonna give you the same tip @hooper gave me like 5+ years ago when I was to get my first pair of P10s. Size acrnm pants lengthwise!
Basically all ACR pants are really wide in the waist and meant to be worn belted. I'm a size 28 waist in most brands (wearing size 27 denim right now) but 180cm tall. I own P10s in both size S and M and while the size S makes for a casual spring pant where I can flash those ankles the mediums fit me much better lengthwise and also give more of that characteristic structural design/drape present in most ACR pants, achieving that iconic silhouette. In the winter I sometimes layer them with sweatpants which makes the effect even more prominent as they fill out the thighs and knees.
Ask around for others with similar body proportions as yourself and see what they're wearing but I'd predict you being probably a size L or so. Just tighten that waist with a cobra belt (narrow enough to pass through the belt loop on the fly) and you'll be fine. Worse case scenario you can always get a good tailor to alter them if the excess material in the crotch area bothers you too much.