Women’s sleeping bags differ from those designed for men because women sleep colder then men, they’re not generally as tall or heavy, and they’re shaped differently with curves and body mass in different places. While the key design elements such as the hood, zipper, and fabrics used are the same across men’s and women’s sleeping bags, the distribution of insulation, shape, and dimensions can vary quite substantially. If you’ve slept cold in a unisex or men’s sleeping bag in the past, we recommend that you buy an anatomically correct women’s sleeping bag to sleep warmer and more comfortably.

outdoor camping cold weather sleeping bag

Here are the main differences between women’s-specific sleeping bags and those designed for men (often called unisex).

Different Body Shapes

Women and men are shaped differently, and women’s sleeping bags reflects this. The build of a women’s-specific bag is often wider in the hips and narrower through the shoulders. This allows more freedom of movement around the hips and less breadth across the shoulders. In addition to better comfort, it takes less energy in terms of body heat for a woman to warm up the inside of a properly dimensioned bag without a lot of unused space, resulting in a warmer night’s sleep.

Different Lengths

Women’s sleeping bags are usually available in shorter lengths because women aren’t as tall as men. For example, many women’s sleeping bags are available in 5′ 6″ lengths (66″) while men’s (unisex) bags are available in 6′ and 6′ 6″ lengths. A shorter female sleeping bag has less interior space to keep warm with your body heat resulting in greater thermal efficiency.

Amount of Insulation

Despite the length difference, women’s sleeping bags may still weigh more than men’s sleeping bag, because women’s require more insulation to stay warm.

For example,  a regular-sized (72″) men’s REI Magma 15 (weight 1 lb, 12.2 oz) has 15.9 oz of 850 fill power goose down insulation, while a regular-sized (66″) women’s REI Magma 15 (weight 2 lbs, 4 oz) has 23.45 oz of 850 fill power goose down. In other words, it takes 3.55 oz of extra goose down to keep a woman as warm as a man even though the women’s version of the Magma 15 is shorter in length.

If you plan on buying a sleeping bag from a manufacturer that doesn’t make women’s sleeping bags, we recommend that you buy a men’s (unisex) sleeping bag that’s rated for 15-20 degrees warmer than you’d originally planned. Thankfully, there are many more women-specific sleeping bags available today from most major brands, including REI, NEMO, Mountain Hardwear, Feathered Friends, Sea-to-Summit, and others so you don’t have to resort to this tactic. It is something you should consider however if buying a unisex quilt.

Insulation Location

The distribution of insulation may also be different in a women’s-specific bag compared to a men’s (unisex) bag. Oftentimes a women’s-specific bag will have a higher concentration of down around the torso and in the footbox. This is based on studies that show where women lose heat at a higher rate, and the extra insulation helps with heat retention. For example, the Feathered Friends Egret 20 women’s sleeping bag has extra insulation in the footbox for women who have cold feet.

Temperature Ratings

Most sleeping bag manufacturers use an industry-standard temperature rating system you’ll see referred to as EN13537 or ISO 23537. They indicate that the sleeping bag has been independently tested in a lab using a standard testing methodology that keeps manufacturers honest when they assign temperature ratings to their sleeping bags.  They also make it possible to compare sleeping bag models across brands, since everyone is playing from the same sheet of music.

The standardized temperature ratings assume you’re wearing a hat and long underwear tops and bottoms in your sleeping bag and you’re using a sleeping pad with an R-value of 4, at a minimum (see our comprehensive list of R-value sleeping pad ratings.)

While the widespread adoption of these temperature rating standards is a huge win for consumers, they’re not a perfect predictor of comfort for everyone. If you know you sleep cold, we’d advise you to use a bags Comfort rating, which is the lowest temperature at which the bag will keep the average “cold sleeper” comfortable. If you sleep hot, you should use the Lower Limit rating, which is the lowest temperature at which the bag will keep the average “warm sleeper” comfortable.

Conclusion

With all of these design and construction factors taken into consideration, you can see that there are some distinct differences between men’s (unisex) and women’s sleeping bags. The good news is that there are a lot more women’s sleeping bags available these days than there used to be at all temperature ranges and price points. If you use a men’s (Unisex) sleeping bag today and sleep cold despite using a high R-value pad and wearing sleeping clothes, you really should consider switching to a women’s bag. It might a profound impact on your days as well as your nights outdoors.