Compressible sleeping bag

you're looking for a bag with a high loft rating.. 800 and above. loft rating is not how much down is in the bag, it should give a seperate rating for how much the down lofts up, for sleeping bags could be anything from 600 to 800, its the volume a known amount of down will puff up to occupy. the highest ratings compress down the best.. exped, rab. some of the macpac ones. i use exped from Bivouac, swiss, very high quality. ultralite range pack down the smallest, but a narrow bag to sleep in, not for people who like space in their bags, they have wider models as well. deepnds where in NZ you're going to tramp and how high. i use bags with 850 loft down i have 300gm of down for summer. i use a bag with 500gm in cooler weather down to around zero. for winter i have a bag with 900gm down bags usually come with a temp rating, they will have three temps, a comfort, limit and extreme. comfort for cold sleepers, limit for warm sleepers, extreme is for survival only and you'll be cold at that temp

Super helpful, thanks @waynowski. I don't need the width but like it as I fling my legs around a lot at night (it's an age thing lol).

you cant move your legs around in the exped bags they are mummy shaped , they keep your legs together.

I don't agree I am a very restless sleeper and sometimes have one leg tucked up and the other stretched out i move from side to side a lot through out the night. I have two exped bags and they are great for moving around plenty of room to move. Just don't buy the lightest range as they are tight. I have a waterbloc800 and a lite500 In fact of all the top quality light weight sleeping bags out there expeds are by far the roomiest

Just don't buy a bag that is too small around the shoulders and hips. Most people make sure they get one that is long enough, but a bag that is too tight in circumference is not obvious until you get it out on a cold night. Then slowly it dawns on you that all that nice high lofting down is being compressed by your shoulders and hips from the inside ... and you can feel these great big cold patches. When that happens, no matter how much you paid for it, you won't be happy. And if you are a restless or side sleeper, then this is an even more important consideration.

I would agree with the recommendations for Exped sleeping bags. I bought a lite 500 a few years ago, and it has been excellent. Nice and light, Well warm enough, Packs down well, and I cant say as Ive had any issues with it being tight fitting. I always have plenty of room to move in it, but Id Imagine the ultralight range are closer fitting. I have also heard good things about the sea to summit sleeping bags, but I haven't used one personally.

Following on from PhillipW's last comment, it is really important thing to think about whether you are a back-sleeper or a side-sleeper. Most sleeping bags are designed for back-sleepers. What this means practically is that the bags are wider than they are high, if that makes sense. So if you lie on your side you will compress the bag on top of you meaning you'll get cold spots. If you are a back-sleeper, this won't effect you. But if you are a side-sleeper, like me, then what I've found helpful is to look for bags that are maybe a bit rounder, rather than rectangular (I don't own an exped, but they look very rectangular to me). The other way to cure this is to just get a larger bag, so that you have room to lie on your side without compromising the loft on the top of the bag. Finally, you may want to consider a quilt, especially for Summer. Because they have no bottom, they will compress a lot more than a sleeping bag and and be a lot lighter. They can also be more affordable than the regular bags we get here. Check out these as an example: www.enlightenedequipment.com.

Those are good points that I had not considered Donald . Though I am a side sleeper I have never felt cold spots with my two exped bags. But in saying that I am generally a warm sleeper.

Shops will let you climb in before you buy, Kokakoco. :) Mummy bags weigh less than comparable rectangulars. Part zips weigh less than full zips that allow you to adjust heat by fully opening. Mummy bags will be warmer than comparable rectangulars. Killing spare air-space is one of the startegies for sleeping warmer. You can always wear more or less woollens at night to compensate for going for a lighter bag. My personal preference is for rectangular down Macpacs because of my large size. Still compresses down to about half a loaf bread size & weighs begger all !