First of all, it depends on where you go (in the suburbs, or into the mountains. For the former, you only need to bring some sleeping equipment and food, even if you don’t bring anything, you can buy it nearby; for the latter, you need to bring all your clothes, bedding, food, and water. Lights, first aid supplies), secondly it depends on how many people you are travelling together (one person, only need to consider yourself, if it is 2 people or even bring a child, you may have to share something for the other person); secondly it depends on the itinerary The maximum replenishment distance (is it possible to get replenishment on the same day, or one, two days or even longer). I have two situations: in most cases, I take my wife and children on the 10-km mountain route, and the family goes camping in the mountains; in rare cases, I follow my travel companion on the camping route for 2-3 days. Therefore, we have prepared several bags: (1) 80L, this is a large volume, it is a long-term bag, in fact, I can’t use it at all (if it’s fully loaded, I can’t carry it on my back), it’s mainly used when taking children into the mountains. , I will carry 2 sleeping bags, spare clothes for 2 people (fleece and light down for morning and evening), 2 moisture-proof pads and other bulky but not very heavy things, as well as stoves, gas tanks, food, spares A small amount of heavy things such as water. We are accustomed to putting things in our bags as much as possible instead of hanging them outside, so that we will have less trouble when passing through bushes and other situations; (2) 60L, this bag is used by my wife, and it is also not full, but it is also for putting her goods and Some heavy items such as food and water are carried in the bag. (3) 40L, this bag is used when I go out by myself. 2 days are enough for one person in spring and autumn. Of course, sleeping bags, tents and other equipment should be appropriately lightweight. Boys recommend 65L, girls recommend 60L. It’s best to go to the outdoor store to try the back first-different heights, body types, and applicable models are still different. You can’t choose only by “how big”. Under the same volume, there are also big, The difference between medium and small size applies to different shoulder widths.