Camping Sleeping Bags
Once a bag stops going in a pack, the entire optimisation changes. Weight is irrelevant, packed size barely matters, and the things that decide a good night are room to move, a shell tough enough to survive a campground, and insulation that keeps working when the tent leaks. That is why synthetic fill and semi-rectangular cuts dominate this category and why the prices are a third of the ultralight equivalents. What does not change is that the lab comfort rating is still the honest number, and that a plush bag on a cold campground still needs a pad with a real R-value under it.
4 of them here from 4 makers, priced $170 to $400. The best warmth-per-ounce of the group is the Kelty Cosmic Down 20 at 0.74 °F per ounce. The lightest is the Kelty Cosmic Down 20 at 2 lb 7 oz, and the cheapest is the NEMO Tempo 20 at ~$170.
Big Agnes
Big Agnes Lost Ranger 3N1 15
Two bags that nest: an outer 15-degree shell and an inner lighter bag, usable separately for summer, together for winter, or as a single mid-weight bag in between. It is the most flexible sleep system in this catalogue and also the heaviest way to buy that flexibility — 44.5 ounces for the pair. For a family or a couple who camp from June through October and want one purchase to cover it, the argument holds. For a backpacker it does not.
Best for: One purchase covering summer through shoulder season
Full spec sheet
NEMO
NEMO Tempo 20
NEMO's entry synthetic bag: the Spoon shape and the Thermo Gills in a heavier 50-denier shell with a lower grade of Zerofiber, at $170. The 50D fabric is the real difference — it is a much tougher bag than the Forte, which matters more in a campground and on a car-camping trip than the 58-ounce weight does. Published ISO lower limit of 21 °F, honest for a bag with a 20 on the label.
Best for: Campground and car-camping trips in a wet climate
Full spec sheetA synthetic mummy with an ISO comfort rating of 24 °F for $189, built entirely from recycled fabric and fill. That comfort figure is the interesting part: at four degrees off its own name it is one of the most honestly labelled bags here, and it is warmer at the comfort end than several down bags costing three times as much. The price is three and a half pounds and a stuff sack the size of a football, which is why this is a car-camping and canoe-trip bag rather than a backpacking one.
Best for: Damp-weather camping on a budget
Full spec sheet
Kelty
Kelty Cosmic Down 20
The bag most people's first down bag is, and reasonably so: 550-fill DriDown, an ISO comfort figure of 31 °F, a semi-rectangular cut with room to move, and $190. Five-fifty fill is low, which means the warmth comes from bulk rather than quality — 16.4 ounces of down in a 39-ounce bag that packs big. As an entry into down camping it is hard to argue with; as a backpacking bag it is beaten on every axis by bags costing twice as much, which is exactly what you would expect.
Best for: A first down bag for car camping and easy weekends
Full spec sheet