Going out for a day hike? An overnight sojourn, or a loop hike over the weekend? Maybe gearing up for a multi-day backpacking trip? The first thing you'll need is a pack. But what size pack will you need? The simplest method for choosing that is breaking down what will actually fit inside one. Read on...
0-10 Liters (The Minimalist)
The realm of lumbar packs, trail running packs and hydration packs, getting a 0-10 liter pack this size means you are committed to minimalism on your day hikes. Expect to fit not much more than:
- A few snacks and gels
- A lightweight rain shell
- A hydration reservoir (packs of this size will not generally have external sleeves for water bottles)
Shop our Minimalist & Hydration Packs
10-20 Liters (The Fast and Light Crowd)
Packs of this size will fit almost everything you need for a day hike as long as you are still using a more fast and light approach. You could feasibly fit:
- Food for the day (a decent lunch)
- A lightweight rain shell
- A light insulation layer, such as a light puffy jacket or vest
- 2 Liters of water  (using a reservoir or 2 1L bottles)
- A space blanket or emergency bivy
- A headlamp
20-30 Liters (The Essential Dayhiker)
The sweet spot for most daypacks, having a pack in the 20-30 liter range will mean that you can certainly carry all of the essentials, up to and including:
- Food for the day (again, a decent lunch)
- A rain shell
- A light insulation layer (a fleece or wool midlayer, or a light puffy jacket or vest)
- 2 Liters of water  (using a reservoir or 2 1L bottles)
- A space blanket or emergency bivy
- A headlamp
- A small first aid kit
30-40 Liters (The Weekend Warrior)
Now we get into overnight and weekend trip-sized packs, provided your sleeping system is packable enough, or if you are hiking with a partner who can carry part of your shelter. A down sleeping bag and ultralight sleeping pad are a must if you want to use a pack this size on overnight and weekend trips. Packs this size also tend to have pockets on their hip belts as well, adding a layer of convenience for storing your knife, headlamp, and snacks. An important note about packs this size and up is that they will be sized to fit different torso lengths, so visiting a shop that specializes in selling outdoor gear *ahem* becomes necessary in order to size your pack correctly. Expect to fit everything that you could fit into a smaller pack, and add:
- A food bag that holds up to 6 meals (count on carrying cold food when using a pack this size, it will be difficult to fit even the smallest pot into one with everything else you'll be carrying)
- A packable sleeping bag (a down bag or quilt in the 35-40 degree comfort range can pack very small)
- A bivy, lightweight tarp, hammock, or ultralight one-person tent (or half of a two-person tent if hiking with a partner)
- A small, packable sleeping pad (a foldable sleeping pad can be easily strapped to the outside)
- An extra pair of socks and underwear
40-50 Liters (The Ultralight Thru-Hiker)
It's amazing the difference 10 liters of space will make. A pack this size can be used for multi-day backpacking trips and even Continental Trail thru-hikes provided you keep a lightweight and minimalist philosophy. For most of us though, a pack this size will simply be a more forgiving volume for our overnight and weekend trips, particularly if using a synthetic sleeping bag, conventional tent and self-inflating sleeping pad, all of which take up more space. Expect to fit everything you could fit in a smaller pack, plus:
- A food bag that can hold up to 5-6 days worth of food
- A pot for cooking
- A camp stove and fuel
- A change of clothes (a stuff sack with an extra pair of socks, underwear, Â some long underwear and a shirt to wear in camp)
- A water filter
- A down sleeping bag in the 20 degree comfort range, or a synthetic sleeping bag in the 35-40 degree comfort range
50-60 Liters (Weekend Warrior Redux)
This size range can be thought of as a "level-up" to the previous size range, in that it will allow you to carry everything you could before, with some extra breathing room if you happen to be using a larger sleeping pad, bag, and tent. Truthfully, this size pack is often seen on overnights and weekend trips as well, simply because the "big 3" (sleeping bag, pad, and shelter) are often bulky if you aren't buying ultra-light variants.
- Even more extra clothes (hey, not everyone wants to be a dirtbag and wear the same thing every day)
- A larger, more plush sleeping pad
- A pillow
- A synthetic sleeping bag in the 20-30 degree comfort range
- A 2 to 3 person tent
- Camp shoes
60-70 Liters (The Conventional Backpacker)
These are the size packs that you are most likely to see when on a multi-day backpacking trip. Inside these you should be able to fit most conventional gear, plus some more creature comforts that will make your trip that much more enjoyable. Taking a pack this size on an overnight or weekend trip could mean that you're perhaps using some older, bulkier, hand-me-down gear, or that you like to go out into the backcountry with all of the comforts of home.
Oftentimes backpacking to a camping spot and posting up for a few days is a great time with a large pack, as you can bring any number of cooking items, drinks, and extra clothes; the hike out is made all the sweeter without the weight of all the food you managed to eat. Expect to fit, along with everything mentioned previously:
- A moderately sized first-aid kit
- Food for up to 10 days at a time
- Extra cookware to make gourmet backcountry food (a frying pan, or an extra pot)
70-80 Liters and Beyond (The Troop Leader)
Being prepared means a lot to you if you are carrying a pack of this size, or perhaps you are carrying supplies for someone other than yourself, such as your children. Carrying a pack of this size, the only limit to what you are able to bring is how much weight you can support on your back! Wearing a pack this size is also a must for porting supplies when doing trail work, or setting up a basecamp at high altitude.
If you're the type of person that packs everything on the gear list, plus redundancies for every situation (Forecast is sunny? Bring a full rain suit anyway! Out for 3 Days? Bring 4 pairs of underwear!) Then you'll want to take a pack that can fit it all. Expect to fit, along with everything else on these lists:
- A 4+ person tent
- A highly insulated, cushioned sleeping pad
- A 0 degree or below sleeping bag, be it down or synthetic