When selecting a backpacking pack, you want something that’s suitable for your type of expedition, comfortable, and lightweight. Here are our picks for the best backpacking backpacks you can buy.

When it comes to backpacking, a lot of factors come into play. In order to select the appropriate pack, you first need to consider what kind of backpacking you’ll primarily be doing. You might want to purchase one pack specifically for overnighters and one pack for extended trips. If you’re a serious thru-hiker, you might want to consider going the way of the ultralight backpacker.

The primary thing to consider is what size pack is appropriate for you. Certain hikers prefer to carry different weight loads than others. There tends to be a general rule of thumb to follow when selecting a pack capacity. For an overnighter or weekend trip, 30 to 50 liters is sufficient. For a multi-day trip, 50 to 80 liters is most appropriate and for extended trips, you’re going to want to go with a pack that is 70-plus liters, unless you decide to go the route of ultralight backpacking, of which you can greatly reduce your load.

Also, it’s important to take the season into consideration. In winter, you’re going to be carrying more layers and therefore want more space in your pack. Your winter backpacking tent might also be heavier than your summer backpacking tent. Think about whether you’ll be doing mostly summer backpacking or taking treks during cold weather.

Especially in summer, you’re going to want a pack that’s well ventilated, so you can avoid sweaty back syndrome, which can lead to uncomfortable rubbing and chaffing. This applies mostly to your back panel and hip belt, your two primary points of skin contact. Suspended mesh panels and ventilation chimneys effectively solve this problem. Our top pick, the Osprey Atmos, features the Anti-Gravity system, which provides for excellent ventilation. It’s important to take into consideration the ventilation features of each individual pack.

While traditional packs are not resistant to the elements, it is something to take into consideration especially when venturing through typically wet and rainy areas. The Hyperlite Mountain Gear Southwest 3400 is naturally waterproof, being constructed from Dyneema, while the Arc’teryx Bora is extremely water-resistant. While traditional pack interiors are often treated with a waterproof coating, water can get in through seams and zippers — to avoid this, we highly recommend purchasing a rain cover. In addition, consider storing your things in dry stuff sacks, which provide waterproofing of their own, especially for your phone, wallet, and other valuables.