Example only: adult, 8°C overnight low, no extra allowance. Change the details for the trip.
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14 selected models · specification panels audited 25/09/2026 · reference prices dated 24/09/2026 · stock and offers are not live. Retailer-stated ratings are not automatically ISO-tested. Review scores are dated snapshots, may cover variants, and do not change the warmth ranking. Highlighted scores are at least 4.5/5 from 20 reviews. Missing fields mean not recovered in this audit, not necessarily absent from the website. Conflicting units and weights are shown, but excluded from the relevant calculations. Product audit notes.
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Choose from the current adult or child range. Comparisons can include bags outside your target.
Explain the difference
Why 0°C rather than −3°C?
Compare the same rating type. If both are published comfort ratings using a comparable method, −3°C indicates colder-weather capability. If one is comfort and the other is limit, the names alone cannot tell you which will feel warmer.
Comfort — colder-sleeper guide: in standard adult testing, the reference is a woman sleeping in a relaxed position. Lower limit — warmer-sleeper guide: the reference is a man curled up to retain warmth. These are test reference bodies, not rules for every woman or man. We display both when published and use comfort for shortlisting. Extreme: a severe-cold survival measure with risk of harm, never a routine sleeping target.
More insulation may add weight, packed size or cost. A warmer bag can be vented where its zip design allows, but that does not make every cold-weather bag pleasant in hot weather.
No extra allowance is applied by default. Use Optional extra warmth if the night may be colder than expected or previous experience suggests a colder rating. An appropriate insulated mat and clothing are already part of the test setup, so a good mat does not earn extra degrees. A poor mat needs fixing; subtracting an arbitrary number cannot correct it.
Rab temperature-rating guide ↗Children & school camps
Adult ISO 23537 temperature testing does not apply to children's bags. A manufacturer's child comfort figure is useful guidance, not an adult ISO result or a guarantee for a child.
Ask about the actual sleeping conditions, the camp packing list, usable bag length, the mat and whether the child sleeps cold. A short camp does not reduce the warmth needed. Match the school’s requirements before choosing the lowest-cost candidate.
A heated cabin may have different sleeping conditions from outdoors; never assume an unheated cabin adds a fixed number of degrees. This tool does not recommend bags for babies or assess infant sleep products.
ISO 23537 scope ↗Fill, lining & outer fabric
| Part | What it changes | What to compare |
|---|---|---|
| Synthetic fill | Often lower cost and more tolerant of damp use, but may be bulkier for a given warmth. | Published warmth, actual weight and packed size. |
| Down fill | Often good warmth for weight and compressibility; needs careful moisture management and drying. | Whole-bag warmth and weight. Fill power alone is not a temperature rating. |
| Lining | Flannel, fleece and smooth synthetic fabrics feel different against the skin. | Feel, drying needs and the specific care label. |
| Outer shell | Canvas and lightweight ripstop fabrics suit different handling and packing needs. | Fabric and construction; no unsupported “durability score”. Water repellent does not mean waterproof. |
Machine washability is product-specific. For example, the Kingsford Junior instructions prohibit tumble drying; other bags permit low tumble drying. Follow the sewn label, dry fully and store as directed.
Anaconda sleeping bag guide ↗Snug, roomy, foot vents & walking
A listed 210 cm bag is 35 cm longer overall than a 175 cm sleeper. That comparison helps screen length, but it does not mean 35 cm of usable spare room: the hood, footbox, seams and insulation take space. Width is normally a flat measurement, not body circumference. Prefer a manufacturer’s stated maximum user height where available.
A snug bag should allow normal movement without compressing insulation at the knees, shoulders or feet. Side sleepers should try their usual position. A wider bag provides room to move, but may bring extra weight and space to warm.
Foot zip: ventilation where documented. Blanket opening: flexibility for warm nights. Wearable bag: a separate design with features specifically intended for mobility. A foot zip or a close fit does not establish that a bag can be walked in. None of this shortlist has been verified as wearable.
Sea to Summit fit and sleep-system guidance ↗