How Much Should a Backpacking Sleeping Bag Weigh?

“Backpacking sleeping bag” is a marketing phrase, not a weight class. The same shelf holds a 550 g quilt and a 1.6 kg mummy bag with the same number printed on the label. Since the bag is usually the second or third heaviest item in a pack, getting the target right is one of the biggest single wins available to a kit.

The target weights

These are targets built from the published weights of the bags and quilts we track, not from a standard. The reference this site measures cold-rated insulation against is the Kelty Cosmic Synthetic 20 at 1,276 g (2 lb 13.0 oz) — a synthetic mainstream 20°F bag — which is roughly where the mass market sits.

What actually drives the number

That last point is why the lightest options are quilts: they delete the zip, the hood and the underside. The Therm-a-Rest Vesper 20 quilt is 550 g (1 lb 3.4 oz) at an EN limit of 20°F, which is roughly half what a full-featured 20°F mummy bag weighs.

Four real bags against the targets

Four bags we track, from the lightest three-season down mummy to the cheapest mild-weather bag, so you can see what each target looks like in a product you can buy.

The Teton is the instructive one. Teton states on its own page that its ratings are survival ratings, and publishes a 45-50°F comfort range for a bag labeled 20°F. So it is not a 1,579 g 20°F bag; it is a 1,579 g 45°F bag. Against the Kelty Cosmic Synthetic 40 at 1,021 g (2 lb 4.0 oz) it saves nothing at all. That is the whole case for reading weight and rating together.

The floor is set by quilts, not bags

If your only question is “how light can this get”, the answer is not a bag. Deleting the hood, the zip and the compressed underside takes a 20°F sleep system from roughly 1,100 g to roughly 550 g — a 556 g (1 lb 3.6 oz) saving, which is more than most people save on a tent upgrade and usually cheaper.

The cost is that a quilt drafts if you are a restless sleeper, needs a warmer pad underneath, and has no hood. Quilt vs sleeping bag sets out who should and should not make that trade. If the answer is a bag, the target weights above are the ones to hold makers to.

What share of your base weight it should be

A useful cross-check: your sleeping bag or quilt should be roughly 10-15% of your base weight. At a 12 lb (5.4 kg) base weight that is 540-810 g, which is quilt territory. At a 20 lb (9 kg) base weight it is 900-1,350 g, which is exactly the three-season down mummy band.

If your bag is more than about 20% of your base weight, it is the right thing to upgrade next. If it is less than 10%, you have probably bought an expensive quilt and are still carrying a heavy tent — check the big three before spending more on sleep.

Not sure what your base weight is? Start with what is base weight, then how to lower it.

When a heavier bag is the right buy

• You camp in sustained damp. Synthetic fill keeps more of its warmth wet and dries faster. That costs 300-500 g for the same rating, and in a Pacific Northwest autumn it is worth it. See down vs synthetic.
• You are not actually backpacking yet. If the bag is for car camping and the occasional mile-and-a-half walk-in, comfort, durability and price beat grams every time. Our backpacking vs regular bag comparison covers that honestly.
• You sleep cold. Going one rating band colder is roughly 150-250 g, and it is cheaper than being awake.
• You need a wide cut. Roomier bags use more fabric and more fill. If a mummy bag feels like a straitjacket, the grams are buying you sleep — see bags for side sleepers.

How to cut bag weight without buying one

1. Bin the compression sack. A compression sack can add 50-60 g and compressing down hard damages it. Stuff the bag loose in the bottom of your pack instead.
2. Pair it with a warmer pad. You can often use a bag you already own at a lower temperature by fixing the ground side. See R-value explained.
3. Wear your insulation at night. A puffy and a hat you are already carrying extend a bag by several degrees, which may let you take a lighter one.
4. Store it uncompressed at home. Down that has been crushed in a stuff sack for a year lofts worse, which is a warmth loss you paid for in grams.
5. Weigh it yourself. Makers publish different figures for different sizes and sometimes for the same one. Your kitchen scale is the only number that counts for your pack.

If after all that the bag is still the heaviest sleep item you own, the ranked options are on best budget backpacking sleeping bags and best 20 degree sleeping bags.