It's a good size for a commuter’s backpack – especially if it includes a laptop pocket. 30-40L: a better size for a long weekend away or a day trip where you need to bring more with you. 40-50L ...

Military Tactical backpack size approx.:13"*20"*11" / 33*50.5*28CM (W*H*D),Capacity: 40L; Military backpack is made of high density fabric--durable and water-resistant Molle tactical backpack has ...

Backpacks with a 20–30L capacity work well for day trips or minimal packing, while 40L and larger are ideal for longer trips. Comfort and Fit: Look for padded shoulder straps, back ventilation ...