What size drybag should be sufficient for an average-sized down sleeping bag?

The ones I’m looking at are sized in liters but I’m not sure what size would be best.

I use a 15-liter drybag with a purge valve for my down rectangular sleeping bag…
It fits well, then I squeeze the air out, close the valve and shove it in that empty space between my foot pegs and bulkhead.

I imagine that if you have a mummy bag or a warm-weather bag, a smaller would do but I find my 15-l is perfect.

Depends on sleeping bag. My one down bag compresses to the size of a foot ball. Then my other bag thats rated to minus 15 is twice as big compressed . Plus the higher cost down bags typically compress smaller as they use the a higher cost down which means it doesn’t need as much to keep you warm. Maybe say which bag you have would help.

I use a “stuff sack” dry bag. I think I estimated size by published dimensions allowing for compressed size. See tech specs…


What the heck is an “average sized” sleeping bag?

I use the Sea to Summit eVent small (10 liter) compression bag for my high quality 20F down regular length sleeping bag, I can put my outer bag cover, an inflatable pillow, and the sleeping bag and compress it to about 2/3 the height shown in the link.
Just the bag would probably fit in the XSmall (6 liter). They purge the air when compressed and are dry bags.

I put long john bottom and top, fast dry 6 pocket pants, wool shirt, fleece jacket, nylon bathing suit watch cap or bacalva, a couple bandanas, and a pair of socks in the medium (14 liter), and it compresses to about 2/3 the height shown.

Not for children, not for big and tall men, not one without the bottom to save weight and volume since it compressed anyway. It’s a “3-season” bag (not for seriously cold weather, but nice in cool weather, and when it’s hot you can use it unzipped). Also, FWIW, I have a mummy style not a rectangular.

@Sparky961 said:
What the heck is an “average sized” sleeping bag?

I put my 20deg regular size lower-end REI down bag (Down Time) in a Granite Gear eVent 18l compression dry bag. After getting the air out, I’m left with about 8 or 9 180deg turns of the dry bag closing mechanism. I’m sure smaller would fit; it depends on how many half-turns you want to keep your down sleeping bag dry.

Roll up your bag and measure it them compare to size of dry bags.

20 liters ought to do you. Sleeping bags are a lot easier to deal with when you use a compression dry sack; stuffing it in is the first step only… ( rolling a bag does not give an accurate estimate). Down retains a LOT of air so you want to get the bag in the bag as best you can then use the compression straps to make it smaller. I use Outdoor Research as I like this compression strap arrangement better than the Sea to Summit


Ditto using a compression sack. If you have the space in your kayak for a 20 liter dry bag, and if you have a compact sleeping pad, you could pack your sleeping pad in the same dry bag. That way you have a bedroom bag with your full sleeping kit, and you only need to grab 1 bag to huck into your tent. Probably also room in there for a small container of Goldbond, a camp pillow, a small book, and a clean set of underwear and socks.

II took a look at what size drybags I use. I have a outdoor research 5 liter dry bag that can hold either my 32F synthetic sleeping bag or my Kelty 20F dri-down bag.Both of those bags compress to small football in size. I have compression bag that came with the one sleeping bag that is use on both sleep bags. Then I use a 15 liter same brand as what Kayamedic posted above but 15 liter instead of 20 liter he linked too. for both a Kelty 0F bag and a minus 15 bag. I cant imagine needing a bigger bag than the 15 liter compression bag. Unless you use one of those cheap rectangle bags you get at walmart. Most decent bags compress pretty small. My main summer bag the 32f synthetic bag i think was only about 130 bucks.

One thought if you are not sure of sizing… it is way better to buy too big and roll extra than not be able to get enough rolls in… Compression straps can always be shortened.

I replaced all my dry bags with Sea to Summit compression dry bags and love them. I also place the S2S dry bag in one of my old bags for extra protection.