Finding the perfect sleeping bag fit.

Sleeping Bags

Getting the right fit.

Often an overlooked aspect of gear fitting, many people give little thought to fitting a sleeping bag. However, the wrong size sleeping bag will leave you out in the cold. Too roomy and it becomes difficult to heat with your body, too tight and the bag is restrictive, reducing insulating ability.

Length

This is the first dimension (but not necessarily most important) to consider in a sleeping bag purchase. Almost all sleeping bags come in lengths. Standard cuts fall in at 6' give or take a few inches. Short and long cut bags fall 6" on either side of a regular bag. A 5'11" individual will still fit into a 6' bag, but a trade-off exists. Extra length allows storage for water bottles, boots, clothing layers (especially useful in winter for thawing, or to prevent freezing). However, this means that your body must compensate by heating a larger area. If your height is a dramatic departure (more than 6") from a given length, you might be spending a few uncomfortable nights burning critical calories to heat the excess space. Ask us about custom construction offered in some of our bags.

Hip and Shoulder Measurements

Taken a step further, it stands to reason that a poor fit anywhere in a bag can compromise performance. As with backpacks, a standard fit or cut bag works best for a vast majority of people. However, some technical mummy bags are cut narrow, reducing the range of application across body types, but reducing weight and improving performance for narrow body types. Consult our specification chart to determine if you'll need a uniquely cut bag. At its widest points a mummy bag should provide room to turn over comfortably, move your arms during sleep (at your sides, in front of your chest), even change clothes. If you're concerned with a particular mummy bag's dimensions please consult our Gear Techs directly.

A Quick Note About Fill Weight

Fill weight in both synthetic and down sleeping bags directly relates to insulating ability. However, fill weights should only be compared to similar fill types. For instance, comparing Polarguard 3D to Primaloft, won't tell you much about fill power, it's apples and oranges. You can however learn a great deal by comparing similar fill bags to their respective temperature ratings. Take the fill weight (insulation weight only, not bag weight), if it is greater than a comparable bag then the temperature rating should be lower. Since temperature ratings are highly subjective and vary greatly between individuals, fill weight takes precedence as an accurate measure of insulative power.

In the end, the fitting of a sleeping bag is part common sense and part personal preference. Many of the most critical fitting factors increase in relevance as the mercury drops below zero.