While most sleeping bags are designed to be most efficient when used independently, some of them are designed to be mated together to form a “double wide” sleeping bag – perfect for a cozy night of sleeping for two. This design feature is most commonly offered on more moderately temperature-rated sleeping bags, because when you zip two sleeping bags together you sacrifice efficiency and compromise the bag’s ability to reach its advertised temperature rating. The reason two sleeping bags paired together is less efficient is because there are more gaps, and more movement is possible, which allows warm air to be pushed out and colder air to enter the bag. If you aren’t sure if you should go with a mummy or rectangular sleeping bag we suggest you check out our previous Mummy Sleeping Bag vs. Rectangular Sleeping Bag post where we compared the two types of sleeping bags against each other.

Mating Mummy-style Sleeping Bags

Mummy-style sleeping bags require that you purchase one left-hand zippered bag and one right-hand zippered bag, in order to zip the two together. Mummy-style sleeping bags mate side-by-side, with the right/left zipper arrangement making this possible. With mummy-style sleeping bags, you determine the side zipper by laying in the sleeping bag face up. If the zipper is on the right side of your body, you have a right hand zipper, and vice versa for a left.

Mating Rectangular Sleeping Bags

Traditional rectangular sleeping bags do not have a right/left zipper designation. The “L” shaped zipper configuration, and the fact that no hoods are involved, allow this simpler sleeping bag design to be mated easily. To connect two rectangular sleeping bags, open both sleeping bags completely, unfold the bags to double their size and lay one on top of the other, lining to lining, and zip together from the middle of the foot of the sleeping bags around the perimeter of the joined bags and voila! You have a double wide sleeping bag. Your best bet for getting sleeping bags that mate together is to purchase them together, at the same time. Manufacturers sometimes change zipper styles, sizes, lengths etc. with each different model year. So, if you do not purchase your sleeping bags together there is no guarantee that your bag will mate with a bag purchased sometime down the road. If you need a double sleeping bag on a regular basis or in colder climates it may be worth looking at one of the options below.

Either way you go have fun camping and be safe!