I give them to you in inches so that I can be a bit sloppy...
Standing the pack up , it is 20" high or 32" including the collar (of course not all of that is usable, you lose about 4" when you roll it up..)
Pulling the fabric outward it is 18" wide.
Once filled the diameter is about 11"
BTW, that is a medium size. The difference between my aprox 20" height and the 24" reported by Martin is how I measured the pack standing up, that is accounting for some deph.