Marmot Tirol 30 Backpack - 1850cu in - 2009 BCS

Elena, this is more of a day pack, you will need a much larger pack for an extended trip.

Mike is right. For weekend trips, a 50-60L is good. For weeklong, most will want a 75L or so. For gear intensive, long trips like mountaineering expeditions, 100L is more common.

You can adjust these if you pack heavy or light, they're just standards. Its a good idea to get a larger bag than you think you'll need, because the suspension will be better with a larger load, you won't have to strap anything awkwardly to the outside of the pack, and you can compress it to have better balance on your back.

For a 3-5 day trip women's pack, I'd recommend the Osprey Ariel http://www.backcountry.com/osprey-packs-ariel-65-backpack-womens-3800-4200cu-in. Get the 65 if you already have or are planning to get a fair amount of backpacking specific gear (i.e. lightweight rain jacket instead of ski jacket, lightweight backpacking tent, light sleeping bag).

Get the 75 if you have a lot of dated, heavier gear, or want to save money at the expense of weight and compressibility with your outfit.

Best of luck!
Simon

I mean... it could be, but it probably wouldn't be as compressed as much as it could be if you did have a compression sack. 1850 cu in is plenty of room to fit a sleeping bag in there.

That's not really the purpose of this pack. It's almost 2 lbs after all. You should be looking for something more along the lines of the Marmot Kompressor.