Very warm, packable and as cosy as your bed at home, the Simond MAKALU II -9° sleeping bag from Decathlon is an exceptional sleeping bag for the cost. Packed full of super high-quality, 800-fill power down, something that’s unseen at this price point, the sleeping bag keeps you warm in the coldest temperatures the UK is likely to throw at you — and does so at an unbeatable price.

Decathlon’s Simond MAKALU II -9° Celsius sleeping bag

Ideal for: Wildcamping, 4-season backpacking, winter adventures

Not suitable for: Campsite camping in summer, ultralight adventures

Super warm, very cosy and a joy to spend the coldest of nights in, the MAKALU II from Decathlon’s Simond brand is an impressive sleeping bag at an even more impressive price. Lofty, packable and lightweight for the warmth it provides, the bag seals in heat and keeps you comfortable down to horrendously cold temperatures in a fit that feels optimised for both back and side sleepers.

The Good

Very affordable

Phenomenal warmth to weight

Comes with both stuff and storage sack

Very packable

800-fill power down is exceptionally lofty

The Bad

The white colour can quickly get dirty

No shoulder baffle

The Simond MAKALU II -9° Celsius sleeping bag review

The MAKALU II is a -9°C rated winter sleeping bag manufactured and sold by Decathlon’s in-house premier mountaineering brand, Simond. Designing some of the most expensive hiking and outdoor gear Decathlon make, Simond is similar to the likes of Forclaz and Quechua — only that you can expect a slightly more mountaineering-oriented product for your money, which in general means lighter, more packable and substantially more technical.

And we’re no stranger to Decathlon. Over the years, we’ve tested dozens of items from the French sporting goods powerhouse, ranging from tents to waterproof jackets, trousers, trail running kit and more. And, so far, we’ve been nothing but impressed. In fact, two items we recently tested, namely the Forclaz MT900 tunnel tent and the Forclaz MT900 -18° Celsius down jacket are some of the highest-rated pieces of kit we’ve ever tested at the Great British Adventure Club. These items offer unrivalled bang for your buck; they’re excellently designed and wonderfully functional pieces of outdoor gear that do everything you’d expect a product from a more premium brand to deliver. Only they do it at a fraction of the price. So how will the MAKALU II, a product that’s a step-up price-wide over anything we’ve ever tested from Decathlon before, fare?

To start, let’s take a look at some details about the bag. The bag we tested was the long version of the MAKALU II, which weighs a reasonable 1,410 g. This puts it bang on par with other down bags with equivalent temperature ratings, although it’s worth bearing in mind that the MAKALU II is anything but ultralight. Regarding temperature ratings, Simond states that the bag has a comfort rating of -9° Celsius, a limit rating of -16° Celsius and an extreme rating of -38° Celsius. Obviously, that means then that the manufacturer doesn’t really recommend you take this thing down to anything colder than -9° Celsius, although it should keep you warm enough to get some sort of sleep down to -16° Celsius. These stats are the product of independent lab testing per the European Standard EN 13537, which assumes you’ll be wearing full-body baselayers, you’ll be camping on an appropriate sleeping pad with a good enough R-value for the conditions, and you’ll be in an equally appropriate tent.

Inside the bag, the MAKALU II features 789 g of 800-fill power duck down, which is exceptionally lofty at this price point. In fact, even sleeping bags 1.5 - 2 times the price don’t seem to come with down this lofty. Rab’s Neutrino 600, for example, a bag with an equivalent temperature rating, is the cheapest bag in their lineup to house 800-fill power down, and it costs more than twice as much as the MAKALU II at £500 (although granted, the Neutrino 600 weighs 400 g less than the MAKALU II, so we can assume that the rest of the bag is made from more premium materials).

What does fill power actually mean? 

OK, so it’s all well and good to tout the ‘fill power’ of the Simond’s MAKALU II. But what does that actually mean? Well, ‘fill power’ is simply a marker to understand the quality of the down used versus the volume. It’s a number that’s based on the amount the down in the sleeping bag lofts back up after being compressed, with higher-quality down lofting up more than lower-quality down. In general, the higher the fill power, the less down you need to deliver the same effect — making for lighter and more packable down-filled products.

For the most part, 400-fill power is the lowest most brands use, rising to 650, 700 and 800-fill power in the lightest and most packable products. Then, at the top end, you’ve 900-fill power down, which is only used in the priciest and most premium products due to the costs associated with sourcing this material. These are the loftiest feathers of them all and are included in bags like the super-premium (and super pricey) Rab Mythic 600.

When bought directly from Decathlon, the Simonds MAKALU II -9° Celsius sleeping bag will set you back £239.99. This makes it considerably more expensive than equivalent budget bags like the OEX Leviathan EV 900, yet — somehow — less pricey than bags like Alpkit’s Skyehigh 900, a bag that offers an equivalent temperature rating to the MAKALU II.

Our experience using Decathlon’s Simond MAKALU II -9° Celsius sleeping bag

To test this bag, we tried to put it firmly through its paces through a busy early winter wildcamping season across the UK. We used it on several 0° C wildcamps across Dartmoor National Park, we used it in a variety of woodland camps where the temperature hovered around freezing, and we put it up against the elements on a sub-zero multi-day traverse of the Western Brecon Beacons, using the bag in temperatures down to the proudly prescribed -9° Celsius. So how did it do?

All in, we thought the bag was excellent — and not just for its price tag. The loft of the down is some of the cosiest we’ve tried, and the speed at which it puffs back up after pulling it out of its stuff sack is quite impressive. Additionally, we also really like the cut of this bag: It fits quite snuggly around your shoulders to lock in as much heat as possible while removing the need for an extra shoulder baffle, and the front-facing zip in the centre of the bag is remarkably easy to operate. Being used to having to zip up sleeping bags along their side, it was a nice change to pull from the centre of the bag. In our experience, this meant that you could simply stiffen out your body to deliver tension to the material alongside the zipper, meaning it was easier to open and close the MAKALU II with one hand than we’re used to from side-zipper sleeping bags.

What’s more, the bag comes with a plush hood that can be cinched down tight over your face until you’ve little more than an air hole to breathe through. When we used this in truly cold temperatures, the hood worked well to keep our heads appropriately warm, meaning we didn’t even need to wear a beanie in this thing, despite using it in temperatures approaching the comfort limit.

Warmth

To us, this is easily our favourite aspect of this bag: It promises it’ll keep you warm down to -9°C, and it actually does that. In fact, in all our years of testing kit, this is the only bag that really delivers what it says it should. Normally you have to shave off a couple of degrees to find the real comfort temperature, but not with the MAKALU II. All in, we slept in this thing almost eerily in line with the European Standard testing framework (see above) and were pleasantly surprised to discover that we stayed comfortably warm. In fact, as a notoriously cold sleeper, all we added to the mix was a thin Patagonia Micro Puff hoody over our full body baselayers when the mercury hit -9°C, which ended up being too much. We had to unzip the bag a little overnight to regulate our body temperature.

Pack size

Regarding the pack size of the Simond MAKALU II, the bag is super compressible. The 800-fill power down smushes down to about the size of a watermelon, so it’s easy to store anywhere in your pack. As ever, if you compress the sleeping bag into a dry bag, you can easily mould it into a more convenient shape for even better portability. If you do that, however, you’re going to want to let the bag loft up after you take it out of the storage sack. You can help it along by fluffing it up, or you can just leave for around 45 minutes or so to properly come back to life.

Durability

When it comes to durability, the bag is made out of a lightweight shell which is actually plenty durable. Snagging this material in the zip doesn’t pose a risk of ripping it and the heavy-duty YKK zippers are smooth and easy to use. All in all, we think this bag is slightly more durable than many other down bags we’ve tested, but definitely isn’t as durable as the less expensive (yet slightly heavier and bulkier OEX Leviathan EV 900).

The looks

Finally, let’s talk about looks. Which, granted, when you’re sleeping in a dark tent on a cold winter’s night don’t really count for much. That being said, we really like the striking white of the outer and the popping red details. It just looks warm — it looks like a campfire amongst a winter blizzard, which makes the whole thing feel even more cosy for some illogical reason. Due to the toilet bowl white outer, however, you do run the risk of the bag quickly getting dirty. As we were careful, ours still looks as good as new after several dozen nights in it, but if you were to use this on a rainy thru-hike or pitch on a particularly wet patch of grass, any smatterings of mud will quickly show up on the MAKALU II, which may or may not matter to you.

Simond MAKALU II -9° Celsius sleeping bag FAQs

Conclusion

Overall, we’re huge fans of the MAKALU II, as we are of lots of other bits of kit from Decathlon. It’s very warm, actually delivering the same levels of warmth it promises to deliver on the tag, packs down into a reasonably small package and is light enough to take on any winter backcountry trip. And all for an even more impressive £239.99.

Coming with a -9 degree Celsius temperate rating, however, this bag will be overkill on anything other than true UK winter wild camping trips.