The Best Sleeping Bags for Camping, Rated by What the Number Means

Kelty publishes both halves of the ISO pair: comfort 31 F and limit 21 F. That single fact separates this bag from most of the category. The number on a bag's label is usually the limit rating, which is the point at which a standardized warm sleeper survives the night curled up — not the temperature at which a standardized cold sleeper is comfortable. Kelty telling you both means you can plan against the honest one.

At 2 lb 7 oz for the regular it is also light enough to carry, which the two big rectangular bags below are not. That makes it the bag that survives the transition from car camping to a first backpacking trip.

Marmot publishes ISO comfort 32.2 F and ISO limit 21.6 F, within a degree of the Kelty on both halves, using synthetic HL-ElixR Eco fill and a recycled polyester ripstop shell. The trade against down is well understood and worth stating plainly: synthetic is heavier and bulkier for the same warmth, and it keeps a usable amount of loft when it gets wet, where down collapses.

If you camp somewhere reliably damp, or your bag will be handled by children, that trade is the right way round.

Coleman lists 75 by 33 in, 5.3 lb, polyester ColeTherm fill and a fit for people up to 5 ft 11 in. It is a rectangular bag, which is roomier and less thermally efficient than a mummy shape — the extra air inside is air your body has to heat.

The honest way to buy this bag is to treat the number as a manufacturer's own estimate rather than a test result, and to give yourself a wide margin. For summer campground camping with a warm pad underneath it is genuinely fine.

The size is the point: 90 in long and 39 in wide is enough for a tall or broad sleeper to move without fighting the bag, which is why many people sleep badly in a mummy. TETON lists double-layer construction with SuperLoft Elite fill and a half-circle hood.

As with the Coleman, the 0 F figure is the manufacturer's own. A bag this large also has a lot of internal air to heat, so pair it with a warm sleeping pad rather than relying on the bag alone.