Going out for the day? Pack marching? 1-3 day training exercise? Multi day backpacking trip? Choosing the right pack begins with what you will be doing with it. There are a few factors that influence what size pack you'll need however, to break it down, ask yourself these two questions;
Although there are plenty of questions to ask yourself prior to purchasing a pack, such as, what's the weather going to be, will I be with others - these two questions will give you a good starting point.
The below is a our guide to get you on your way.
The most popular sized packs, the lower end of this scale is generally for the minimalist and those looking for a fast and light day hike. 0-10L will give you a hydration bladder and room for a snack whereas, 20-35L where most people would fit in to. Designed to carry all you need for a day without any unnecessary items, work necessities such as a laptop or folder or a bit of camera gear etc.
These packs are great for overnight hikes, deer hunting and generally any adventure from 1 - 3 days. I would stay around the lower end of the scale if I was looking at an overnight stay. 35-40L you will be able to fit a sleeping bag, plenty of food, clothing, basic shelter and possible a sleeping mat. Although some like to embrace the packing light option, you'll need specific gear such as light weight clothing, lightweight tents etc however, don't get caught out as weather will play a big role here. 40L-55L packs will allow you to stay a little longer or make that shorter stay a little more comfortable. Food and water can take up quite a bit of room in your pack if you're away more than a couple of days. The larger end of this scale allows for packing that little bit extra such as cooking gear, extra clothes etc.
The longer you're out in the great outdoors the more room you'll need. Although this size pack is great for 1-3 nights (if you're sleeping bag, pad and shelter isn't small), I would suggest this size for those longer adventures. The main difference between these packs and the 1-3 day packs is the need for extra food and a little more technical gear.
If you plan on being outdoors and leaving civilisation behind, then this pack is what you will need. The only limit here is how much weight you can carry on you back. This pack is also great if you're carrying gear for others (such as family etc).
There is a fine line between everything you need and too much stuff! Just remember to carry what we dub the 10 essentials: