Which pack size?

[rowdy]

When purchasing a new pack how do you decide which size you need? 50L, 60L, 70L?

Aside from drawing on previous experience is there a reliable way to estimate your needs? I think the old adage of if you have the space you will fill it applies so I'm looking to buy the smallest pack that suits but just not sure how to go about it. Would appreciate any advice from the more experienced out there.

Thanks

[Lamont]

The method that keeps popping up on redditUL to determine that Litre Capacity number which you are asking for is-
get a box bigger than your load, put all your stuff in it, squash it down a bit, measure the level on the side of the box. Do your calculations and go from there.

For example 40cms X 40cms (width of your box) X 30 cms high (measure of your stuff laying in the box) equals 48000 cubic centimetres, which equals (from google calculator) a 48 litres capacity required for everything minus your food. This method is good because it doesn't suppose an ultralight, lightweight or standard load it just reflects what you are using.

This system may involve more than one rucksack if you want the smallest rucksack- as you said you did-one for the bulkier winter load and one for other weather. One sack to rule them all means a bigger sack than you probably will require for the bulk of the year.
ps -Don't forget to estimate your food "space"for the appropriate days you may need and a smaller sack to me means no bladder(take up too much space) -use the pockets on the outside.
Weigh it while you are at it so once you know your litreage you can look for something to accommodate the weight.
If you are thinking of getting some new (lighter/smaller) stuff, obviously do all of this before you buy the rucksack!

Cheers.

[nq111]

It may not be the fashionable view anymore but I still subscribe to the view get a bit bigger than you think you need.

A slightly larger pack is bugger all weight penalty and most modern packs compress down really well to a smaller load.

I don't buy the idea that you fill the size pack you have. Most people are more careful about minimising weight and just pack what they need.

[wildwanderer]

- buy all your equipment before buying the pack. Buy the lightest and most compressible/compact gear you can afford and which is appropriate for the foreseeable conditions you expect to be camping/walking in. Especially pay attention to the compactness and weight of the more bulky gear like the tent,sleeping bag and cooking gear.

- Only then buy your pack. As a rough guide many are happy with under 50L for up to 4 days. If your camping in the snow or in cold windy conditions or in constant wet conditions you may need more gear.

- I can recommend the osprey exos packs in the 48L size as a good pack for up to 4 days, is comfortable and reasonably inexpensive. And is a good overnighter pack if your just starting out.

- Unless your going for a couple of weeks (and carrying all your food for that length of time) or in the army you dont need a 80L or even a 70L pack.

- You will be alot more comfortable and find the trip easier with a smallish and light pack

[Huntsman247]

Yeah depends how much self-control you have. I hate having to do oragami on all my stuff to get it to fit. And having a larger bag allows me to have a better packing/finding stuff experience. And if you do an odd trip that requires you bring an unusual amount of water or gear it still fits in your bag without having to tie everything on the outside. Different trips/seasons require different kit.
I know what my essentials and luxury items are and if I'm going to bring a luxury item it's got to earn it's board.
My old pack was just right and I always found myself wishing it were just a tad bigger when trying to pack it.

Figure out how much stuff you carry and go bit bigger.
You can always cinch it down but can't make it bigger.
Just view it as an opportunity to develop self control.

[trekker76]

As folks above say generally you would want to know what gear you are carrying and how long you'd like to head out for( more time means more rations to carry). I always suggest folks go and check out pack sizes in person. Even a cheapo camping store or chain like BCF will have 50, 60 or70L packs on the shelf. Ask the store if you can bring your gear in there to stuff it for sizing, even if you don't want the pack you get an idea what 60L or 70L means. Then you just work out how many tins of food per day you expect to cram in there as well. Personally I only have two packs, a 35L daypack which gets me around malls, day trips and overnighters. And a 80+20L expedition pack which I don't mind carrying smaller loads as it has a comfortable frame I am used to.

[ofuros]

Overall it depends how bulky your bushwalking gear is...very bulky equals larger pack, less bulky smaller pack.

But length of adventure, included activities(abseil, packraft), season 3 or 4), tropical or temperate walking etc etc, all play a part too...

My gear is usually packed into 3 or 4 dry bags...so you could take them with you into a bushwalking shop and find a pack to suit.

[GPSGuided]

Obviously direct trial and error is the most accurate. Short of that and a little margin, for 3 seasons and an overnight camp, the following reference to the weight volume category of your gears should match reasonably well.

Seriously UL (Zpack, tarp camp and willing to give up on creature comfort) - Under 30L
L to UL (Tarptent, down sleeping bag and premium lightweight gears) - Under 40L
Average (Kathmandu/Rays heavier consumer gears) - Under 50L
Heavy (traditional canvas gears) - Prayer for your back.

[rowdy]

Thank you for the great responses folks, that's given me a good head start.

I'll try to do an accurate calc using one of these methods but I think I'll fall in between the Average to light scale shown by GPSGuided with a mix of traditional consumer and some UL gear.

[GPSGuided]

There’s no harm to drag you main items (tent, sleeping bag, mat, cooking) to a shop and trial fit their backpack options. Just leave spare room for clothing, food and water.

[trekker76]

That's another point too. Longer range expeditions, ultralight or very lightweight takes a degree of expertise to understand and master, both in selecting gear and packing and compressing items to a degree. Also your food, developing knowledge on high energy/dense/low water weight foods. Just something to keep in mind if you aim at any extreme levels, for beginners some generosity in your measurements might be a good idea. You can always upsize or downsize once you see which way the hobby takes you.

[LachlanB]

Obviously direct trial and error is the most accurate. Short of that and a little margin, for 3 seasons and an overnight camp, the following reference to the weight volume category of your gears should match reasonably well.

Seriously UL (Zpack, tarp camp and willing to give up on creature comfort) - Under 30L
L to UL (Tarptent, down sleeping bag and premium lightweight gears) - Under 40L
Average (Kathmandu/Rays heavier consumer gears) - Under 50L
Heavy (traditional canvas gears) - Prayer for your back.

50L for average gear seems optimistic. I have a 65L pack, and my average-to-light gear basically fills it with 3 days food. But that's without extreme packing.

[GPSGuided]

50L for average gear seems optimistic. I have a 65L pack, and my average-to-light gear basically fills it with 3 days food. But that's without extreme packing.

Margin of error and for overnight, not 3 days. Obviously some care and choice are required, or move to the next category.

The OP really should borrow a pack to try out a trip or try packing them in a shop.

[north-north-west]

Then you just work out how many tins of food per day you expect to cram in there as well.

Who goes on multinight walks with tinned food?

[LachlanB]

50L for average gear seems optimistic. I have a 65L pack, and my average-to-light gear basically fills it with 3 days food. But that's without extreme packing.

Margin of error and for overnight, not 3 days. Obviously some care and choice are required, or move to the next category.

The OP really should borrow a pack to try out a trip or try packing them in a shop.

I guess one thing to keep in mind is that 65L isn't necessarily 65L... My pack is a Black Wolf pack, and they're known for having packs slightly smaller than the competition for a given value. I suspect there'd be a bit of variation between other brands too.

[warnabrother]

I used a 48L Exos for 8 days on the OLT and had room to spare..
It all depends on the volume of your gear.

[LachlanB]

It all depends on the volume of your gear.

Which is usually pretty large for someone starting out. I don't know about the rest of you, but when I was putting together gear for my first multi night walks, it was a mix of bulky camping gear, one or two specially bought things, and stuff raided from the kitchen.

Over time that's got smaller though- for instance my full length S2S mat takes up about 1/3 of the space that my 3/4 length Denali mat did, and is warmer to boot. But for many years, I could only just fit 15kg of equipment for an overnight walk in a 65L pack.

[photohiker]

I used several packs over time. Most of them were above 70L and heavy.

The over time was becoming unhappy carrying a large and heavy pack. I could do it, but was causing wear to me and not that happy about walking with it. Love hiking. Went to a physio carrying my normal pack loaded with a multiday trip system containing it all. The physio did a complete test of my body without the pack and then with the pack. They then sat me down and asked me if I want to continue hiking carrying the pack - of course, I did want to continue. The physio asked me if I had to much stuff in the pack? and I explained that I only carry stuff I really need except the photography gear. The physio then said I should find ways of reduce the weight well below the 20+kg if I still want to go hiking.

It took time to find good and lighten items. For the pack, I swapped the nice and relatively pack to the Mariposa Plus in 2010. Weighed around 800g which was less than half the other packs I had used. The end of the process the pack with all the gear was 6.8kg for my TGO trip 2013 http://bellavist.com/?page_id=551

[GPSGuided]

The physio then said I should find ways of reduce the weight well below the 20+kg if I still want to go hiking.

It took time to find good and lighten items. For the pack, I swapped the nice and relatively pack to the Mariposa Plus in 2010. Weighed around 800g which was less than half the other packs I had used. The end of the process the pack with all the gear was 6.8kg for my TGO trip 2013 http://bellavist.com/?page_id=551

What? Just a RX100 camera? You gave up 12.5kg in photo gears? [FACE WITH TEARS OF JOY][FACE WITH TEARS OF JOY][FACE WITH TEARS OF JOY]

[trekker76]

Then you just work out how many tins of food per day you expect to cram in there as well.

Who goes on multinight walks with tinned food?

Food tins as in slang for food containers.

[photohiker]

The physio then said I should find ways of reduce the weight well below the 20+kg if I still want to go hiking.

It took time to find good and lighten items. For the pack, I swapped the nice and relatively pack to the Mariposa Plus in 2010. Weighed around 800g which was less than half the other packs I had used. The end of the process the pack with all the gear was 6.8kg for my TGO trip 2013 http://bellavist.com/?page_id=551

What? Just a RX100 camera? You gave up 12.5kg in photo gears? [FACE WITH TEARS OF JOY][FACE WITH TEARS OF JOY][FACE WITH TEARS OF JOY]

Have never taken 12.5kg of camera on a hiking trip. Is that what you carry GPSGuided?

Back before then, I was using a Lumix GF1 for hiking trips, but it was failing just before the 2013 trip. Got wet on a trip and they ain't waterproof. Took the RX100 and it worked well for a 220 mile trip in two weeks. Wouldn't drag my Canon heavy 5D with the 17-40 on a long hiking trip, but did it in Tas. They were short distances compared to the other trips I normally do. Didn't have a Fuji X-T2 until 2016, but that is the usual one I use now on my trips.

Have carried the X-T2 with a couple lenses on my hikes in the Mariposa.

[GPSGuided]

Have never taken 12.5kg of camera on a hiking trip. Is that what you carry GPSGuided?

You know that I was in jest earlier, right?

But seriously, for all the time I short changed my camera gears on trips in the name of weight reduction, I regretted later. Tried iPhones, tried Nikon P7000, Since, returned to satisfaction with a compact dSLR and a suitable lens of 24-120 range. More recently went across to mirrorless and a 24-240. Maybe it's my perception, I just miss that long lens to pick out details. Weightwise it's bearable.

[Ms_Mudd]

On pack weight itself, I would like to throw this into the mix. Sometimes a slightly heavier pack carries more comfortably and is worth having a little extra weight for the sake of your back.
I got a fairly minimalist pack to reduce base weight further and found it carried comfortably enough for a quick overnighter, but either wearing it on more than 2x consecutive days or loaded with a slightly heavier food carry (anything above 12-13kg total weight) would make it feel less than optimal to carry.
I have gone back (pun intended) to my heavier pack with its blissful suspension which has added 800g to my base weight, but weight well spent as far as my back is concerned. I also carry a heavier than absolutely necessary sleep pad (at 800g) for the same reason, my comfort is paramount and I would rather shave weight of in other areas than be in pain with a sore back after a trip.

Also, and this is not scientific at all, I think some manufacturers must measure their pack volume in some quirky ways as I have seen some that seem like the tardis inside while another in the same volume capacity is significantly smaller and like trying to cram a family of 10 into a Daihatsu Charade. Perhaps it is pocket location etc that does that and doesn't make as good use of the volume?
Up shot is, try and get somewhere where you can compare a few and try them on, or if you live rurally like me, take your chances on a well priced buy, get out there (while looking after the gear!) and give it a go with whatever pack you choose. If it doesn't work out there is usually a healthy second hand market for quality gear.

[photohiker]

The issue is the design of the pack, not the weight of it.

I hunted for a well designed pack that was as or more comfortable than a heavier pack. It used to be difficult to find a lighter pack because they were not available in retail shops, manufactured by small company. Way more of them now from the large manufacturers and able to test them at retailers. Have a look at the Osprey 48L - 1.2kg

Wouldn't carry more than 12-13kg in any pack.

[Ms_Mudd]

True, true a well thought out design is paramount rather than actual weight, absolutely agree. I guess my point was saying don't necessarily steer away from packs that may be a bit heavier if they are a better, more comfortable fit for you than something lighter.

I would like to stay around the 13kg max, but sometimes on a multiday with bigger water carries,food, maybe fishing gear I end up more like 15-16kg , but am comfortable enough with it if using the pack with the more structured frame.

[wildwanderer]

I think that a reasonable point and mirrors my own experience also. My Osprey exos 48 is great however once over 14-15kg mark the comfort level goes down and a more padded and beefer frame would be more comfortable. With the Exos once the weight goes over 14-15kg the load transfer mechanism from shoulders/back to hips starts to struggle.

Still.. I try and carry less than 14kg for all walks of 5 days or less.

[peregrinator]

The issue is the design of the pack, not the weight of it . . .

Yes, that's probably a fair summary. Which is why some people prefer Aarn packs. (I use one, but have no connection with the manufacturer.)

[photohiker]

The issue is the design of the pack, not the weight of it . . .

Yes, that's probably a fair summary. Which is why some people prefer Aarn packs. (I use one, but have no connection with the manufacturer.)

Yep. They were excellent. I used Aarn packs for a long time until I realised it is better to reduce the weight in the pack and wouldn't then need the weight of the Aarn to carry the contents. Aarn Peak Aspiration was the best I had, it was a little heavier than the current version and is about an extra kg compared to my Mariposa.

[trekker76]

It all depends on the volume of your gear.

Which is usually pretty large for someone starting out. I don't know about the rest of you, but when I was putting together gear for my first multi night walks, it was a mix of bulky camping gear, one or two specially bought things, and stuff raided from the kitchen.

great example, for me it was a bunch of mil surp kit included, not the lightest gear around. Some lucky folks may enter the hobby with a perfect inventory, but I certainly wasn't one.

[LachlanB]

It all depends on the volume of your gear.

Which is usually pretty large for someone starting out. I don't know about the rest of you, but when I was putting together gear for my first multi night walks, it was a mix of bulky camping gear, one or two specially bought things, and stuff raided from the kitchen.

great example, for me it was a bunch of mil surp kit included, not the lightest gear around. Some lucky folks may enter the hobby with a perfect inventory, but I certainly wasn't one.

The fun bit is when you look back and realise: "I took that on a walk?!?!"