You’ll need a backpack in the 30-40 litre range. The “litres” refer to the interior space of the bag. The 30-40L size range is larger than a daypack but much smaller than the kind of pack that you would take on a backcountry hiking trip or for your summer abroad in Thailand. u003cbru003eu003cbru003eI’m a 5’4” (165 cm) tubby woman and my pack is 38 liters. Clothing size matters, so if you are a petite women, you may be able to get away with 30 liters. If you are a big guy, 40 may work better for you. u003cbru003eu003cbru003eBe sure to check out our u003ca href=u0022https://wayfaringviews.com/camino-de-santiago-packing-list-women/u0022 data-type=u0022postu0022 data-id=u00221478u0022u003eCamino packing listu003c/au003e. It has everything you need (and nothing more) Everything on the list will fit into a 35 litre pack with room to spare for snacks and water. u003cbru003eu003cbru003eIf you already have (or can borrow) a larger 45+L bag, you can certainly use it for the Camino. But be sure not to overfill it.