How to Choose a Sleeping Bag
A good sleeping bag is one of the most important pieces of camping gear you'll own. It affects your comfort, warmth, and ultimately your enjoyment of the outdoors. This guide covers everything you need to know to make the right choice.
1. Temperature Rating
The temperature rating tells you the lowest temperature at which the bag will keep you comfortable. This is the most important specification when choosing a sleeping bag.
Understanding Temperature Ratings
- Summer bags (35°F+): For warm weather camping when temps stay above freezing
- 3-Season bags (20-35°F): Versatile bags for spring, summer, and fall - the most popular choice
- Winter bags (20°F and below): For cold weather camping and winter expeditions
Pro Tip: Buy a bag rated 10-15 degrees colder than the lowest temps you expect. If you "sleep cold," add another 10 degrees. It's easier to vent a warm bag than warm up a cold one.
EN/ISO Ratings
Look for bags with EN (European Norm) or ISO testing. These standardized tests provide three temperatures:
- Comfort: Temperature at which a cold sleeper stays comfortable
- Lower Limit: Temperature at which a warm sleeper stays comfortable
- Extreme: Survival temperature - not for actual use
2. Fill Type: Down vs Synthetic
The insulation inside your sleeping bag is what keeps you warm. There are two main types: down and synthetic.
Down Fill
Down is the fluffy undercoating from geese or ducks. It's the gold standard for sleeping bag insulation.
- Best warmth-to-weight ratio
- Highly compressible
- Lasts decades with proper care
- Loses insulation when wet
- More expensive
Fill Power Explained
Fill power measures how much space one ounce of down occupies. Higher numbers mean better insulation with less weight:
- 550-600: Good quality, budget-friendly
- 650-750: Better warmth-to-weight, mid-range
- 800+: Premium quality, best for ultralight backpacking
Synthetic Fill
Synthetic insulation uses polyester fibers to mimic down's properties.
- Insulates when wet
- Dries quickly
- More affordable
- Hypoallergenic
- Heavier and bulkier than down
- Loses loft faster over time
Choose Down If: You need the lightest, most packable bag and camp in dry conditions.
Choose Synthetic If: You camp in humid or wet conditions, have allergies, or want a more affordable option.
3. Shape and Fit
Sleeping bags come in different shapes that affect warmth, comfort, and weight.
Mummy Bags
Tapered shape that's narrower at the feet and wider at the shoulders.
- Most thermally efficient
- Lightest weight
- Most packable
- Less room to move
Semi-Rectangular Bags
A compromise between mummy and rectangular shapes.
- More room than mummy bags
- Still reasonably efficient
- Good for side sleepers
Rectangular Bags
Traditional box shape with equal width throughout.
- Most spacious
- Can fully unzip to use as blanket
- Often zip together for couples
- Heaviest and least efficient
- Best for car camping
4. Weight and Packed Size
How much your bag weighs and how small it packs matters most for backpacking.
Weight Guidelines
- Ultralight: Under 2 lbs - for thru-hikers and fastpackers
- Lightweight: 2-3 lbs - good for most backpacking
- Standard: 3-4 lbs - versatile, budget-friendly
- Heavy: 4+ lbs - car camping only
5. Features to Consider
Hood
A well-designed hood is essential for cold weather. Look for:
- Drawcord to cinch around face
- Differential cut to prevent cold spots
- Comfortable when tightened
Draft Collar
An insulated tube around the neck that prevents warm air from escaping. Essential for bags rated 30°F and colder.
Draft Tube
An insulated flap along the zipper that blocks cold air from entering through the zipper teeth.
Zipper
- Full-length for ventilation and easy entry
- Half-length saves weight
- Two-way zippers let you vent at feet
- Anti-snag design prevents frustration
Stash Pocket
Internal pocket for storing small items like phone, headlamp, or watch.
6. Budget Guidelines
What to expect at different price points:
- Under $75: Basic synthetic bags for car camping and occasional use
- $75-150: Quality synthetic bags, entry-level down bags
- $150-250: Good down bags, premium synthetic bags
- $250-400: High-quality down bags with premium features
- $400+: Premium ultralight down bags for serious adventurers
7. Care and Maintenance
Storage
Never store your sleeping bag compressed. Use a large cotton or mesh storage sack that lets it stay lofted.
Washing
- Down bags: Use down-specific soap, front-loading washer, tumble dry low with tennis balls
- Synthetic bags: Regular detergent, gentle cycle, tumble dry low
- Wash only when necessary - spot clean when possible
Drying
Always ensure your bag is completely dry before storing. Damp insulation leads to mold and mildew.
Quick Decision Guide
For Backpacking: Mummy shape, 20-30°F rating, down or quality synthetic, under 3 lbs
For Car Camping: Rectangular or semi-rectangular, any temp rating, synthetic is fine, weight doesn't matter
For Winter Camping: Mummy shape, 0-20°F rating, down with DWR treatment, quality draft features
For Budget Camping: Semi-rectangular synthetic, 30-40°F rating, focus on value brands