Minim 400 Down Sleeping Bag: K Series

Warmth to weight at the limit of possibilities with this 'K Series' version of our classic lightweight bag. Minimalist design cuts weight, but not warmth.
Typical Operating Temperature
Guideline minimum temperature. Sleeping Bag TOT: you should get a night’s sleep, under normal circumstances. Clothing TOT: you should feel warm enough, assuming low/moderate activity. Sleep System TOT: relates to full system. For more details, see our Technical Briefing.
-5°C / 23°F
For clothing, weight is for size: M. For sleeping bags, weight changes with selected length/width. N.B. there may be some variation in the weights of finished products.
585g / 21oz
Minim 400 Down Sleeping Bag: K Series

Wonderful, excellent and so light for the warmth. Everyone (in the Atacama Crossing race) was very jealous. Thanks again for such a great product.
Rhianon West



  • PHD 'K Series': Ultimate warmth / weight performance
  • Unique PHD 1000 fillpower down
  • Superlight MX outer fabric
  • Inner: Superlight 10X fabric. Down-proof, wind proof and super soft
  • Box-wall construction for max loft
  • Hood draws up close around head
  • Packed size*: 17 cm x 28 cm
  • Footpiece: Ovoid shape to fit naturally to feet & avoid pressure; multibox section covers whole foot area
  • Straight-wall baffles for lightness
  • Stuff-sac & mesh storage bag supplied
  • Colour: Black
  • Set options:
    • Ultrashell water-resistant outer. An excellent balance of weight, water-resistance and breathability
    • Waterproof Dri-LX outer fabric shell (+220g)‡
    • Long or Short zip (protected by single draft tube)
    • Slim, Wide and Extra Wide widths†
    • Short, Long, and Extra Long lengths†

*Please note: we make our stuff sacs big enough to allow fairly easy stuffing rather than reducing the bag to the tightest minimum.

‡Please note: The optional waterproof Dri-LX outer provides an extra seam-sealed outer shell to the bag. While a shelled sleeping bag is not designed to be used alone in heavy rain (the hood area is open to the elements) the shell does protect the bag when it is used outdoors without a tent.

†Please note: For all length and width options we change the amount of downfill to keep the warmth (TOT) the same.


This K Series product has been created for one single reason, to take warmth-for-weight performance to the limit of what's possible. Unique 1000 down, super-light materials, and specific design features mean that the word Ultralight now applies to this wide range of gear that will take you to the Poles as well as on a Sahara Marathon. More on the K Series...

As deceptively simple as the rest of the Minim range, the Minim 400 K delivers what everyone wants from an ultralight sleeping bag: full performance for the least weight, just that with no frills. PHD's extraordinary 1000 down ensures the performance, while the 10X inner helps to bring the total bag weight right down to a remarkable 585gm.

The bag has a hood and box-wall construction throughout, but there's no zip, no collar, no side-block baffles. What you get instead is a small package which will tuck with no fuss into a corner of your sac, ready to give you a good night's sleep when there's frost on your tent.

The optional waterproof Dri-LX outer provides an extra seam-sealed outer shell to the bag. While a shelled sleeping bag is not designed to be used alone in heavy rain (the hood area is open to the elements) the shell does protect the bag when it is used outdoors without a tent, for example in a snow-hole or under a tarp.

Dri-LX (weight: 64 gsm)

At just 64gsm, Dri-LX is our lightest 2-layer breathable waterproof rip-stop nylon fabric. Its remarkably low weight not only makes for a lighter load, but also reduces pack size. Its excellent waterproofing qualities are in part due to how it can be taped at the seams to create a waterproof shell for sleeping bags and clothing.

Ultrashell (weight: 40 gsm)

One of the lightest of PHD's coated materials. This ripstop nylon provides complete wind block and good water resistance at minimal weight. Ultrashell gives an excellent upgrade to performance with very little weight penalty.

Superlight MX fabric (weight: 32 gsm)

A mini-ripstop nylon with excellent tear strength, MX is the pick of the superfine 15 denier downproof materials. We have tested lighter fabrics, but most have had significant drawbacks, while our confidence in MX is based on several years of extensive use in both our ultralight and our high mountain gear.

Ultralight 10X fabric (weight: 26 gsm)

10X, PHD's first 10 Denier Fabric. 9,000 metres of the yarn used to weave 10X weighs just 10g, that's about the same as a £1 coin! For all its thinness 10X is amazingly downproof and with reasonable care will go on giving you good service for years.

Sleeping bag zips

  • No zip: The standard design on our lightest bags with open hoods. The simplest/lightest system which is a must for adventure racers. Up to 140gm (5oz) lighter than a full zip with draft tube.
  • Full zips: Full zip bags ventilate well, so they can be used over a wider range of temperatures.
  • Short zips: Short zips are lighter and pack smaller than full zips. A short zip & draft tube is up to 85gm (3oz) lighter than the full version.
  • Our full briefing on sleeping bag zips.

1000 fillpower down

This rarest of all downs we reserve for the K Series. European goose down of unique quality. 1000 provides the highest warmth-for-weight performance possible from down. More on our down insulation.

"I have just returned from the Atacama Crossing multi day race in the Atacama desert in Chile. I used a Minim 400 'K Series' bag for the race. The nights in the desert were freezing, literally, the temperature dropped below 0C every night. Everyone else in my tent really struggled with the cold and I slept without socks and in a short sleeved top every night in my wonderful sleeping bag. It really was excellent and so light for the warmth too. Everyone was very jealous and those runners doing other multi day races took down all the details so hopefully you get some more orders. Thanks again for such a great product."
Rhianon West.

The reviews relate to standard Minim 400, which is 85g heavier

Backpacking Light - Recommended

"The Minim 400 matches Backpacking Light's ultralight principles and earns our Recommended rating based on its simplicity, minimal weight, and high warmth-to-weight ratio. It's especially suited for ultralight backpacking situations when getting the most warmth with the least weight is the most important consideration and when too-warm night time temperatures are not an issue, i.e. when no ventilation features are needed."
Janet Reichl, Backpacking Light review.

"My minim 400 sleeping bag did an excellent job of keeping me warm in sub-zero temperatures in Scotland this March, even though I was just sleeping under a basha. Peter Hutchinson Designs is certainly my manufacturer of choice for down-filled sleeping bags and clothing."
Dr. Richard Tofts.

"I have recently returned from successful completion of Marathon des Sables. Have to say I loved my Minim 400 sleeping bag, great design, incredibly lightweight. I hate being cold and was worried about getting a good nights sleep in the desert - my PHD was like a comfort blanket, slept well at just the right temperature (used a silk liner also but then I really don't like the cold!). Can thoroughly recommend."
Michaela McCallum.

"I have had a minim 400 and love it, probably one of the best investments I have made in gear."
Jason Pryke.

"[The Minim 400] is an absolute delight. It's extremely light and has no zip, so it's fail-safe. Most importantly, it packs down to a tiny size. This is the nearest you can get to carrying just the 800-fill power-down filling."
Geographical Magazine.

"I would like to thank you for my Minim 400's performance, used it twice so far at -4C, no base layers etc, fabulous backpacking bag for winter."

"The Minim 400 sleeping bag is the dog's *******s!"

"I have just returned from working as an International Mountain Leader in Patagonia with a group from Chelmsford Girls School for Bull Expeditions. This is possibly a first in winter for this type of trip in the Torres del Paine massif. We had night time temperatures of -18C. I took a Minim 400 and was toasty warm in it; I did keep my hat on and a pair of down bootees. I would like to thank you for a great lightweight product that does the job I ask of it."
Stuart Smith.

[Editor's note: Stuart is obviously a hardy sleeper! We don't normally recommend the Minim 400 for these conditions]


"I used the Minim 400 for the last three weeks in the Alps while climbing and I am very satisfied. Awesome quality even when using it for a bivy in bad conditions and snowed under."
Stefan Pinckney.

"My main backpacking bag for 2 years on long distance trips--sleeping in a bivi bag in the UK (a tough test). It is unbeatable for warmth to weight, packs tiny, keeps me very warm (I feel the cold) and dries easily from slightly damp bivi nights. Unbeatable!"

"I'm very impressed ... down leakage ... has been substantially lower than ... products ... by other manufacturers ... I took the bag out for a test in the hills recently. I'm certainly glad I specced a zip on the bag, as it's so warm I needed it! Nice and lightweight, and wonderfully warm. I've recommended you to friends and colleagues, and will continue to do so."

"Many thanks for sending the Minim 400 in time for the Original Mountain Marathon. My wife was full of admiration for the bag―she said it was perfect for the conditions."

"As a veteran of 14 Karrimor mountain marathons I have found nothing to beat the Minim 400 Down sleeping bag."
John D.

"I ... have a minim 400 which is superb."

"I've got one of your minim 400 bags and like it very much having used it several times on Scottish 3-season trips."

"Thanks again for ... the sleeping bag and [the] help I received from your staff in picking the right bag. The Minim 400 was both light and very warm - just the thing for a multi-day event with desert nights [the Marathon des Sables - ed]."
Dr Ben Edwards, Senior lecturer, Research Institute for Sport, Liverpool John Moores University.

"I have been very impressed with the Minim 400 bag you made for me (although your -5 deg C rating for the bag is far too conservative!)"

"A compliment rather than an enquiry. I took part in the KIMM at the weekend using a Minim 400 bag. Sub-zero temperatures at the overnight camp with icicles on the tents and many competitors complaining of the cold. I was too hot! So warm, so light. Thank you."

"My Minim 400 bag arrived perfectly. I tested it last week and am very happy. The bag performed very well over a large range of temperatures. For example I used the bag during a 12 deg C night, had a good night's sleep and found the bag very breathable. Subsequently, in the field, at 0 deg C, with a strong wind and under just a tarp (no tent) the bag was warm, and I had great night of sleep. Fantastic! Your PHD Minim 400 is now my number one bag, and I have some good bags, including SW Ultralight and Marmot Hydrogen. Congratulations you make a fantastic piece of gear."
Eduardo Lartigau, Brazil.

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