Marmot Atom Down Sleeping Bag

1°C Comfort Limit (EN13537:2012), 235g of 800 Fill Power Down (US Method)
Weighs 640g (Regular bag)
Code: SS21253V
  • From £219.99
  • (FREE UK & EU Delivery)
  • RRP £289.99
+ In Stock Now   |   Usually dispatched within 24 hours

The Atom is back! The winning combination of low weight and small pack size make this great 2-3 season bag. It features 800+ fill power hydrophobic down, a full length zipper, lots of loft and an extremely effective hood design.

Marmot says:

Ultralight for backpacking treks and overnights in mild temps, bring the Atom 40° Sleeping Bag when you want to keep pack weight at a minimum. Its certified 800-fill-power-down insulation—protected by a Down Defender treatment, curved baffles, and a Pertex® Quantum shell—will keep you warm as you sleep. Comfortable extras like the anatomically designed footbox, multi-baffle hood, and secondary zipper for ventilation make this lightweight sleeping bag hard to leave.

Marmot's Atom Down Sleeping Bag has been updated and reintroduced in to the range. Now using 100% recycled material for the shell it still offers a great balance of quality, low weight, packability, and performance. It uses 800+ fill power down protected with Marmot's Down Defender to help the down to stay dry longer, loft better when damp and dry more quickly than untreated down. The new recycled Pertex Quantum fabric offers a combination of lightweight and good durability plus it's DWR coating will offer some water resistance. The fabric feels really soft which allows the down to loft freely and the slightly brushed feel of the Microlight lining fabric is extremely comfortable against your skin.

The +1°C Comfort Limit gives you some flexibility for using it into spring and autumn when paired with a good insulated mat. All the usual features are present with a bag of this quality plus the  additional small 'fold-down'  second zip which allows you to roll the top of the bag down. This is perfect for a warmer night to avoid overheating or for a cold evening where you want to be sitting in the bag inside the tent.

- Reviewed by BasecampGear

Help and advice:
  • Certified 800-fill-power-down insulation offers lightweight warmth; water-resistant Down Defender finish provides an extra level of moisture protection and retains critical loft of the insulation 
  • Pertex® Quantum nylon is designed to protect from wind and improve the efficiency of insulation; shell and lining fabrics are 100% recycled for reduced environmental impact 
  • Smooth, curved baffles reduce down shifting; nautilus multi-baffle hood limits heat loss 
  • Anatomically designed footbox with wraparound construction increases warmth and room for feet 
  • Main 2-way, full-length zipper with anti-snag slider and insulated draft tube; secondary fold-down zipper provides added ventilation and easy access 
  • Interior stash pocket stows small camping gear 
  • ISO tested for temperature rating 
  • Filled and finished in Rohnert Park, CA


  • Regular bag weighs: g
  • Regular length fits: 183cm
  • Fill weight: 235g
  • Zip: Left hand zip
  • Interior length: 206cm
  • Shoulder width: 155cm
  • Hip width: 142cm
  • Foot width: 113cm
  • Stuff sack dimensions: 15.2 x 30.5cm



  • Long bag weighs: g
  • Long length fits: 198cm
  • Fill weight: 290g
  • Zip: Left hand zip
  • Interior length: 221cm
  • Shoulder width: 160cm
  • Hip width: 147cm
  • Foot width: 117cm
  • Stuff sack dimensions: 15.2 x 30.5cm


Temperature Ratings

  • EN Rating Comfort limit: 42°F / 6°C
  • EN Rating Lower comfort limit: 34°F / 1°C
  • EN Rating Extreme limit: 7°F / -14°C


  • Insulation: 800+ Fill Power Goose Down with Down Defender, RDS down
  • Shell Top: Pertex Quantum© 100% Recycle Nylon Plain Weave
  • Shell Bottom: Pertex Quantum© 100% Recycle Nylon Plain Weave
  • Lining: 20d 100% Recycled Nylon
Be the first to review Marmot Atom Down Sleeping Bag. Write a review ›