Choosing a sleeping bag is an important decision to make, especially with so many styles to choose from, and designed for different purposes. In this guide, we’ll focus on sleeping bags designed for backpacking: discussing different styles, and outline key features to look for when you go shopping around.
Much like choosing other backpacking gear (like tents), first you need to identify the type of backpacker you are. Are you a minimalist, carrying only the bare essentials, and concerned with reducing weight in every way possible, or are you interested in providing the most comfort, and will carry the extra weight to get it? Or maybe somewhere in between? With sleeping bags, this is tricky question; while it is ideal to save space and weight, one does not want to sacrifice warmth, loft, and comfort.
Lightweight models are most prevalent in the outdoor market and offer the best of both worlds, so for the purposes of this guide we will focus on these models.
The most important factor to consider when purchasing a sleeping bag is the temperature rating. This is the lowest temperature at which the bag will keep the average sleeper warm, i.e., a 20-degree bag will keep someone warm no lower than 20 degrees Fahrenheit. These ratings can make it difficult to compare different bags because the manufacturer, rather than an independent evaluator determines the ratings. In addition, individuals sleep at different comfort levels; it has been scientifically proven that women sleep colder than men. The best recommendation is to use the temperature ratings as a guide when shopping for a sleeping bag.
We should take the time to mention that recently there has been the emergence of a more uniform rating system known as European Norm (EN) 13537. This temperature-rating methodology has been in use for European-manufactured sleeping bags for a few years now and is slowly being adopted by US manufacturers like REI and Marmot.
So what time of year and where will you be doing the majority of your backpacking? Take the time to research the climate, and nightfall temperatures where you will be hiking. Even in the summer months at higher altitudes the temperature can drop considerably after sunset, and you will want a bag rated for those temperatures. However, here is a general guide to follow:
| Season | Temperature Rating (°F) |
| Summer | +35° and above |
| 3-season | +10° to +35° |
| Cold weather | -10° to +10° |
| Extreme cold | -10° and below |
Now that you have narrowed down the temperature rating you are looking for, what type of insulation do you choose: down or synthetic? Down-filled bags use the fluffy plumage of geese or ducks to form the insulating factor in the bag. If looking at down-filled bags, it’s important to understand fill power. Fill power is the measurement of the loft or ‘fluffiness’ of a down product and the cubic inches of displacement that one ounce of down fill will create, and correlates with the insulating value and overall product weight; higher fill power equates to better insulating properties and less overall weight. With the added insulation and reduced weight comes a much higher price tag with higher fill power sleeping bags.
While down is the prominent insulation in most backpacking sleeping bags, it’s important to note that down loses its insulating properties when wet. Manufacturers try to prevent this by constructing bags out of waterproof and breathable fabrics or treating the shell with a water-repellent. If you plan on backpacking frequently in very wet climates, it would be best to consider synthetic fill bags.
The alternative to down-filled bags are synthetic-filled bags, usually comprised of some sort of polyester fill. Synthetic fill retains much of its warmth even when wet, are quick-drying, and non-allergenic (in most cases). However, with the security, comes added weight. Though technology is advancing and many synthetic bags are coming close to the weight of their down-filled counterparts, you will still have to haul a few extra ounces to get the equivalent warmth of a down bag. Also, each time you stuff a synthetic bag, you lose a bit of its original loftiness. However, synthetic bags generally have a lower price tag.
Sizing is another important feature to keep in mind. While all true backpacking sleeping bags will have the same general ‘mummy’ style cut, the sizing will vary between manufacturers. For the best fit, refer to each product’s length, shoulder, and hip girth measurements. A narrower bag will provide more efficient insulation, but some might find it restricting to sleep in that style of bag. Women-specific bags have different proportions than standard sleeping bags, most notable features are the shorter length, narrower shoulder girth and wider hip girth. To get you started, refer to this general chart for length sizing:
| Men’s | Women’s |
| Short: up to 5’6″ | Regular: Up to 5’6″ |
| Regular: 5’7″ to 6’0″ | Long: 5’7″ to 6’0″ |
| Long: 6’1″ to 6’6″ |
Other features to look into are zipper compatibility (allowing you to attach two bags together for cozier backcountry camping with your mate), a hood (to keep your head warm), draft tubes and collars (to prevent warm air from escaping through the zipper and around the hood), pad loops (for attaching your sleeping pad directly to your bag), and stash pockets (for keeping small items like a watch, iPod, or glasses close by).
Good luck! Next week we’ll offer a few tips to help make your sleeping bag last for many seasons.
