This post is part of the Backpacking Gear for Beginners course.
Why do you need a sleeping bag?
Sleeping outside is going to get a little chilly. We need something to keep us warm at night.
Sleeping bags are compact bags of insulation that keep you warm at night but doesn’t take up much space in your pack.
Sleeping bags will be one of the largest, heaviest pieces of gear you will take. If possible get something lighter.
Another option instead of a sleeping bag is a quilt. This won’t be the duvet from home but rather a blanket made of lightweight materials like a sleeping bag. Quilts don’t have a bottom like a sleeping bag. They just attach to your sleeping mat and use that as insulation underneath you. They can be good for warmer weather backpacking.
Rectangular or mummy
There are 2 mains hapes to sleeping bags, rectangular and mummy. Rectangular are larger rectangles with squared off edges, usually without a hood. They are great for car camping in warmer seasons. They aren’t as lightweight or warm as mummy bags.
Mummy bags are rounded around the bottom and have a hood. This saves weight in the bag, saves space inside (less to warm up) and keeps your head warm with the hood. We recommend a mummy bag for backpacking.
Mens or womens?
Sleeping bags are usually split up into mens and womens versions. Womens bags will be shorter lengths and have slightly more insulation.
Synthetic or down
Insulation in sleeping bags is what keeps you warm. It’s either made from down feathers or synthetic insulation.
Down feathers will be lighter, pack down smaller and be more expensive. Down feathers don’t insulate well so be careful keeping down bags dry. Most down will come with a water resistant coating that lets it dry faster. At the end of the day the warmth comes from how large, or fluffy, the down can expand, or loft. Wet feathers won’t loft as high.
Synthetic insulation is made from plastic. There are many kinds and some expand and pack down very well. Others don’t. Synthetic sleeping bags will be less expensive than down. Synthetic insulation stays lofted and warm even when it’s moist from sweat or condensation in the tent.
Sleeping bags are usually rated for their temperature they can keep you warm at. There are 3 different zones: Comfort, Transition, and Risk. These come from a standard test with a mannequin with base layers on. The exact temperatures you get cold at will be different for everyone but it’s a rough guide.
The Comfort range is where a woman (women tend to sleep cooler) would be comfortable. For example this range might be down to 0 Celcius (32F). This is where you want to be sleeping.
The Transition range is where a man in a curled up position would just be able to stay warm. For example, this range might be down to -6 Celcius (20F). You can still use your bag in this range and maybe adding a bit more clothing would help. Don’t plan on doing it a lot.
The Risk range is where hypothermia is possible. Don’t use the bag in these temperatures. In emergencies it might be your only choice so it’s better than nothing. More clothes, and sleeping bag liners will make it warmer.
If all your backpacking will be above 0 Celcius (32F) getting a bag with Comfort rating 0 will work well. It might be a bit warm during warm summer nights but you’ll only need 1 sleeping bag. If you can afford it, getting a smaller lighter bag for warm trips will save weight in your pack.