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How Many Days of Food Can You Pack in a Bear Canister or Ursack?

How many days of Food fit into a Bear Canister or Ursack

There’s a simple rule of thumb for figuring out how many days of food you can fit into a bear canister. Find out the capacity of your bear canister in cubic inches and divide by 100. That will give you a pretty good approximation of the number of days of food you can cram into it. For instance, if your bear canister has 500 cubic inches of capacity, you should be able to fit 5 days’ worth of food into it.

See the table below, where I’ve precomputed the number of days for all of the popular bear canisters and Ursacks bear-proof bear bags that backpackers and campers use where bear-resistant containers are required.

Make / ModelWeight in oz.Cubic InDays Food
BearVault BV45033 oz4404
BearVault BV50041 oz7007
Garcia Backpackers Cache43.5 oz6146
Frontiersman Insider Bear Safe48 oz7357
Wild Ideas Scout28 oz5005
Wild Ideas Weekender31 oz6506-7
Wild Ideas Blazer33 oz7507-8
Wild Ideas Expedition36 oz9009
Bare Boxer26.3 oz2753
Lighter1 Big Daddy43 oz6503
Lighter1 Lil Sami28 oz3003
UDAP No-Fed Bear38.4 oz4554-5
Grubcan Bear Resistant Container43 oz5745-6
Counter Assault Bear Keg58 oz7167
Ursack Major Bear Bag (10L)7.6 oz6506-7
Ursack AllMitey Bear and Critter (10L)13 oz6506-7
Ursack Major XL (15L)8.8 oz9259
Ursack Major 2XL (10L)15.7 oz183018
Ursack AllMitey Grizzly Bear and Critter (20L)13.8 oz122112
Ursack AllMitey Kodiak Bear and Critter (20L)15.3 oz185018-19
Ursack AllMitey Bear and Critter (30L)15.3 oz185018-19

When packing your food, your goal is to fill up every nook and cranny inside the canister so that it is full of food without any gaps between items. For example, you’ll want to move it out of hard-sided containers, like boxes, and repack it with “soft” containers like plastic sandwich bags that will pack flat or will flow around other items. For example, oatmeal, nuts, rice, beans, m&ms, etc., are best repackaged without the boxes or extra packaging they often come in. The same is true of freeze-dried Mountain-House-style meals, which come in bulky rehydration bags. You can move them to a small plastic bag and rehydrate the contents in a cookpot, kept warm with a cozy or your sleeping bag, instead.

Make sure to leave some room in your bear canister for the other “smellables” that you need to pack away at night, including your toothpaste, scented lotions, etc. Basically,  if it goes in your mouth or on your skin, it needs to go in your bear canister.

When packing your food, there’s no need to pack your first day’s food in the bear canister, because you’ll eat it before it needs to be stored away. Store it in a smell-proof plastic bag in your backpack, so it doesn’t make your gear smell. People often overlook that first day, but carrying it separately can really extend your range.

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  1. As I remember there was a gentleman that packed a 450ci bear can with crushed cookies. He figured out that it had enough calories at roughly 160cal/oz to let him go out three weeks at 4000cal/day. I think of this as a bit ridiculous. Pemican is a more dense food at around 220cal/oz. (Ha, hey!)

    Seriously, 100ci/day is a good number. Bulk packaging for things like rice, couscous, macaroni, coffee, cocoa, etc will save a lot of volume. About the same as removing as much packaging as is possible. Dehydrated (freeze dried) foods help some, though this is primarily for weight reduction. High density foods, help a lot, too. You can usually get another day or two out of a 500ci can like this, without major adjustments to your diet.

    • Variety. I’ve found the most important thing when packing food is keeping it interesting and not it’s caloric density. None of us are going to starve to death but you will get pretty uncomfortable if you get sick of eating the same high calorie item over and over again…

    • I remember reading on a backpacking forum that one guy got 35,000 calories into one bear canister by packing it with all Snicker bars.

    • Make your last day with rice. After you get everything else packed in, pour the rice – say a cup – over the top. Fills all the nooks and crannies. Or, if you’re travling with a dog, break up the kibble and throw the the last day’s two or three cups in on top to fill all the nooks and crannies.

  2. I experimented with a Bearikade Weekender a few years ago and was able to cram in 7 days’ food for me plus my dog (I had to crush the dog kibble, and, for me, use extremely compact foods like couscous instead of noodles or rice). That meant I could carry 8 days’ worth. Of course Wild Ideas/Bearikade containers are not certified by the IGBC (they didn’t pass †he grizz test), so cannot be used anywhere that requires IGBC certification. I wish I’d known that before I bought one!

  3. Very informative Philip, great article, I don’t have any experience with bear canisters, I backpack pretty much exclusively on the east coast ( Virginia, North Carolina, and Tennessee) but I am interested in the safety bear canisters provide for everyone involved including the bears. Quick question, should tabacco and other smelly smokable products be stored in a hanging bag or canister?

    • It can’t hurt. Bear are attracted to things that smell period, so smelly tobacco probably qualifies.

    • Nicotine is horribly toxic, which is why it is used as a pesticide. If a bear were to eat a few cigars or something, it might poison him.

      • Bear definitely eat and enjoy Tobacco products. I smoke a pipe and often leave my pipe and pouch outside on my deck, and bears will take it more than half the time. I had a mule that did the same thing.

  4. Should one put trail-cleaned pots and cooking / eating utensils, and Esbit cubes (ewww) and stove for cubes in bear-safe containers?
    I assume that the answer is “yes”, but of course I could be wrong. It is hard for me to imagine bears being interested in stinky Esbit.

    Should one put other-fuel (alcohol, canister, white-gas) stoves and windscreens / foil under stove (if there is no adherent food spillage) in bear-safe container?
    I assume that the answer is “no”, but of course I could be wrong.

    • I often do store that stuff in my bear safe container (Ursack or Garcia) especially if I’m creeped out where I am…camping alone in unfamiliar territory.
      Of course, I only do it in countries that have bears. Not all do. :-)
      I think if your pots and utensils are clean, you’re probably ok. I guess it depends on the type of bear and how much risk you’re willing to tolerate.

      • Black bears, Missouri Ozarks. They haven’t become accustomed to campsite raiding…..yet. Most people car-camp. The number of bear sightings per year is in the high hundreds. 10 years ago, maybe 50 sightings at most. It is a success story for MO Department of Conservation. The park / forest / conservation area rangers and educators have been promoting bear awareness. No selfie-with-bear maulings or near misses yet, to my knowledge.

        Well, I suppose that I will not bother with packing utensils and pots in the bear canister – I have the weekend size Bare Boxer. Defends against raccoons and rodents too!

        Re: the scourge of Selfies With Large Wild Mammals:
        At a county park with a small elk herd, every year some bozo tries to selfie close to a rutting elk, and gets shoved (relatively gently) or threatened by the Lord And Master. LAM sees lots of people year round and isn’t terribly threatened by “Trailrunner minimus” or by “Hydrocarbon fumigatus”, but some nitwit always tries to stomp on LAM’s last nerve in rut season.

        Local newspaper article with ridiculous photos of one incident.

  5. I live in the same area as Aaron. I put anything that smells in a bear-proof bag. (Usually an Ursack, unless a hard canister is required.) Chapstick, sunscreen, bug repellent, etc. Bears are notoriously inquisitive, investigating anything unusual, not just food. Raccoons, skunks, and other critters can also be that way, though bears are more formidable. I’m surprised Phillip recommends “scent-proof” OpSacks, though. My only experience with those is kids trying to hide marijuana. If I can smell dope right through one of those bags, I assume a bear can smell Snickers bars. I have no science to back me up, though.

    • Those guys (the Loksak) people have gotten a lot of bad press from the hiker community, but the reality is those bags are smell proof. (The FBI even uses them as evidence bags.)
      They’re just not smell proof if your hands are dirty and you touch the outside of the bag (with your pot crystal-covered hands).

  6. Used to put my favorite bagels in a sandwich bag and bounce on them till they were cardboard thin. Got my 95-year-old mother-in-law to help squish bagels. She thinks I am special. Her daughter didn’t when I poured a weeks worth of loose homemade granola in our bear canister to fill the voids. Never did that again. Heard about it each time she dug into the bear canister.

  7. I use the Ursak and like that it can be folded and compacted as you use contents. Not as bulky as a canister but you can’t sit on it.

  8. To the olive oil carrier..try butter in the wnter. It’s neater ‘cause you can eat it with a spoon!

    • Read an article by a mountain runner in Alaska that rolled butter cube slices in brown sugar. Sounded good, I never tried it. maybe colder weather only?

  9. The issue of packing away your utensils should take into account of how clean they really are or more to the point is how did you wash them. I had a bear take interest in my cooking pot that I had scrubbed clean with Dr Bronners peppermint soap. My pot was taken away by the bear that loved the smell of peppermint. I should have known better but thought that I had it rinsed out well.

  10. Sometimes rather than repack into a Ziploc bag I just take a needle and poke holes in the original packaging right before a trip. For example ramen (which I squeeze to make it crumble), mountain house or bag’s of m&m’s just poke holes in the bags and let the air out and there is no need to repackage it, it will not smell much or go bad before I can eat it but it will help to pack it down tighter. This especially works for me when doing a resupply.

    • That’s a good one. I do the same thing with bags of potato chips and smash them up so they pack small. As long as they’re eaten quickly, they don’t absorb funky flavors.

  11. Repacking the freeze dried meals is what I do also but with one small exception. I usually keep two meals in their original packages. One I reuse to heat the repackaged meals in and the other I use as garbage pouch because it seals tight and keeps my bear can cleaner. 7 well fed days in a BV500 is very accurate in my experience.

  12. On the AT this year I learned a tip from fellow hiker Pringle. For the hard to open Bear Vault BV500 type canisters. Put a thin store card (not a credit card), in front of the divet on the canister and slide the lid divets past the store card on the canister.

  13. Pack that sucker full of organic peanut butter!
    I had a 5 gallon tin of it back in the ’60’s and it took over a year to get to the bottom. You could toss in a few raisins for variety if the weight is not a concern.

  14. Terry Lovelette

    We have managed 12 days for two with a BV500. We made dehydrated meal packs in sandwich bags, had various bars, beef sticks, string cheese , tortillas, snickers, mustard, and peanut butter packs. With the meal packs, bars, and tortillas, we poked a hole in the packaging with a pin to let the air out then folded the package over and sealed it with scotch tape. We pressed and packed the canister layer by layer until it was chucked full. We ate our way down day by day. A little hungry at times but we lived, we walked, and we reveled in the great expanse of the Sierra Nevada. Since that trip, we went back two other times but added a BV450. Same fun less hunger…

  15. I was able to fit 7.5 days into a BV450 for the long JMT stretch between MTR and Whitney.

    It took some obsessive repackaging, packing akin to a tetris game and ration control to 1.3 lbs/day but it was doable and I wasn’t hungry. I carried one extra day outside to be consumed that day.
    It was just right.

    • I did the same thing with my BV450 on my JMT trek. Worked great. Everything was calorie dense but varied for interest. I dehydrated my own meals and rewrapped all bars in saran wrap for added space saving. Filled all the spaces with something.

  16. I think you’ve got the wrong number of days listed for Lighter1 Big Daddy; you list it as three days, same as Lil Sami. It should probably be 6-7 days.

  17. I am curious about the general consensus on whether or not it is necessary to put a JetBoil into a bear canister if it has only ever been used to boil water that is poured into something else to rehydrate food. I can see the potential for getting some of the food on the JetBoil (particularly the neoprene sleeve) and thus causing it to have some odor, but I don’t see this as likely as getting some on your clothing that would not get put into a bear canister either. Definitely interested in what others think.

  18. A very interesting wee article, where I live we do not have bears but we do have vermin which at times are very keen to share in trail supplies necessitating food hangs with nylon monofilament fishing line. There is one slight problem for those who do not live in the USA trying to convert avoirdupois to universal metric ie grammes per cu cm and back again to use the 100 rule. I am in danger of developing a severe headache!

    • Some rough (close enough) conversions:

      1 oz (by weight)=28.35 g
      1 oz (liquid)=30 cc
      1 ramen (totally made up unit of measurement equal to volume of 1 ramen noodle package)=22 cubic inches=.36 liter

      Don’t use these formulae if trying to land spacecraft on other planets, unless of course, your calculations are in ramens.

  19. I rarely use a bear canister, but I still repack FD meals in foodsaver bags. It seriously reduces the bulk of the food, AND the trash. Unless it is a legal reqt. I use and Ursack and Opsak

  20. For those who have problems attaching a bear canister to a backpack, Harbor Freight sells a four dollar, 3 oz, 12″ x 18″ motorcycle cargo net that could be rigged up as an elastic pouch/pocket to carry a bear canister. It has 6 plastic hooks that can be removed and replaced with ‘biners. I bought one for another purpose and thought, “This could really be useful.”

  21. It all depends what kind of food you bring, how you package it, and how good you are at packing the canister. I fit seven days worth of food in the BV450 on a Yosemite backpacking trip. I copied an article from the early internet with directions for packing 20 days worth of food in a Garcia. I used that article as the basis for my week long trip. I wasn’t eating crushed cookies. As a matter of fact I prepared a steamed chocolate cupcake each night for dessert. The article is likely still out there.

  22. Something I’ve always wondered – all food and smellables go in the can but at the end of a day, without a proper shower – aren’t we one big smellable? I mean, even with brushing your teeth (which has an odor) your breath is a constant odor factory all night (after loading pepperoni into your ramen) . You also have remnants of lip balm, bug spray and sunblock. And supposedly a bear can smell 20 miles away – so he’ll walk by your tent not smelling anything? Sometimes when I’m going crazy in the evening making certain I found everything with an odor in my pack or on my person to put in the can I start thinking “this is silly”. And yes – every morning I always find a half eaten bar in my hip belt I missed :(

  23. Old pro tip to get extra air out of Ziploc bags to compress them down without crushing the contents: Fill the bag and seal it except for a small slit at the end of the zipper. Push the bag down into a large bowl of water while keeping just the open corner above water. This forces a lot of the air out. The plastic will conform to the shape of your contents. Pinch the zipper slit tight before removing the package from the water. Works well on chunky items such as meat, cheese, chunks of large chocolate bars, bagels, carrot & celery sticks, dried fruit slices, etc.

    • A bear standing on your Ziploc bag should also compress it quite well… I haven’t yet experimented with my theory but I’ll be happy to write up the results for those who try.

  24. I use bv450 for 7-9 days in high mountains (10.000’+).
    Full freeze dried dinner every day. Nuts and seeds, chocolate bits, dried mango and some other fruits.
    I’m 80 kg man.
    So it stated 4 days is with some horrible packing skills ;)

  25. I always use those one oz peanut butter (or other nut butters) packs to stuff calories into the nooks and cranny’s

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