Backpack Capacity (DaveBugg Bait!)

[Malachiuri]

After many years of backpacks I have come to the conclusion that pack manufacturers may all be either drunk or part of a Matrix level conspiracy.

How in the Holiest of Hecks do they determine the Litre capacity of backpacks? I have 28L packs that hold as much as one of my 40L packs in the main compartment. My new 50L actually holds less than my 40L.

I know they supposedly pack every compartment that can be closed with a zip, velcro, or roll and clip and take measurements from there, but sometimes I really think they are just making this stuff up for marketing.

How about just give us the main compartment volume as one metric and accessory space as another??

There. I got it off my chest.

/Rant off; preload/rant2(printerink.arrrg)

M

 

[VNwalking]

/Rant off; preload/rant2(printerink.arrrg)

Now that you mention it...I always wondered why my '28L' daypack struggles to hold ¾ of that amount, and why my '50L' camino pack actually has about 40Ls of useable space.

So I deal with it by shrugging and ignoring the numbers - but rather paying attention to the practical and actual capacity of both packs. That's why it's best to buy a pack in person rather than online. That way you can see the truth of things, rather than being bamboozled by imaginary numbers.

 

[Chenahusky]

Back in the day, 1970s, I worked in the outdoor trade. Our principal rucsack supplier/ manufacturer used to fill the sacks with dog biscuits and then re-measure, in containers. It seemed to work. I am sure that they now use complex algorithms, not so much fun though.

 

[Harland2019]

I always thought that they filled it with water! Now that I am now far more intelligent (!) I checked online - a 25-litre backpack should hold 1,525 cubic inches of "stuff" that can be bent into the available space!

 

[Paul Wilson]

I read on the Decathlon website only yesterday that they fill the bag with small balls then decant them into a measuring container, how strange this should come up then today

 

[Dandabika]

As long as it can carry what you absolutely need and it weighs as little as possible, it doesnt really matter. I've used 5 different packs that were rated at either 40 or 50 litres. They all did well. Just make sure there's always enough room left withought squishing fresh bread, fruit, and vegetables when you can get some.

 

[Malachiuri]

I read on the Decathlon website only yesterday that they fill the bag with small balls then decant them into a measuring container, how strange this should come up then today

Not really, it is an issue that has been beleaguering the brightest minds of countless generations.

I am willing to bet that there were guys hauling rock chips in ancient Egypt who swore that basket held more than his buddies.

M

 

[wabana]

My 50L OSPREY only holds 47950 cubic centimeters- not 50,000 ! and I am not happy about it! BUT it does hold all my @#$^&^%!! now that i am purging 10% of the stuff i thot i was going to bring and have shed 4 lbs (1.7kg), 2 (0.9) to go. Ie., TEVA universal sandals GONE in favor of 1/10th weight flip flops ( $2 vs. 50!

 

[MichelleElynHogan]

The smart money is looking to minimize pack size and weight anyways. Some may consider reduced capacity as a favour to the buyer over a sneaky little rip-off? For me, I’m down to an HONEST, 30L Pack that is so well designed, it can be scrunched up into a pocket pack. (Made by the folks that brought us the Hobo-Roll).

 

[Malachiuri]

While I wrote this post partly in jest, it is actually anchored in some concerns I have about pack sizing.

Recently I was having a discussion with a buddy who is going on Camino with me in January. As usual, my recommendation to his was to NOT buy a pack till he had all the stuff he needed to carry and then buy the most efficiently sized backpack for his load. Once he got his packing load dialed in, he started looking and was dismayed at the variation in packs with supposedly the same capacity.

We are spoiled in our area that we have an REI, Scheels, Cabelas and Academy all within a 20 minute drive. Not everyone does. I can see the randomness of pack sizing to be a real hassle to other folks who don't benefit from ease of shopping like we do.

My gripe is not about how much you should carry, or how you carry it, but an honest and accurate metric across all manufacturers to help folks decide without a bunch of Amazon returns.

M

 

[DyanTX]

25 or so years ago when I got interested in wilderness backpacking and reading forums - it was espoused that 100 cubic inches could hold 1 pound of gear. That made a 4500 cubic inch pack able to contain 45 pounds. Then they started using liters (or maybe both liters and cubic inches). The conversion factor then became 1 cubic liter = 60 cubic inches. So then 40 liters = 2400 cubic inches = 24 pounds of gear. Has worked pretty well on the Osprey and Kelty packs I've owned, from 75 liters (45 pounds carry) down to 20 liters (12 pounds carried). Outer pockets - if any - included.

 

[davebugg]

I might be able to shed some light on why this variation of Stuff Holding Capacity occurs. First let me make a distinction in terminology which may help with any confusion folks might have on the subject.

Backpack 'Size' is the measurement that describes the 'fit' of the pack. It typically refers to the user's spinal length from the bump at the base of the neck, to the point of the iliac crest of the hips.

Manufacturers will each have their own charts which describe how they match spinal length (inches or centimeters) to their backpack's range of sizes: XS, S, M, L, XL OR XS/S, M/L, XL.

Backpack 'Capacity' is the measurement of volume for carrying stuff. It used to be solely expressed as the volume of the main compartment and did not include outside pockets or hipbelt compartments or those tiny compartments for holding keys, change, cell phones, or the larger pouches to hold hydration bladders.

Nowadays, all compartments, pouches, pockets, and secret stashes are measured for volume, including any pockets on hipbelts or shoulder straps. There is also no universal standard by which a manufacturer must use a specified methodology for assessing these volume measurements.

The above definitions mean that within a specific model of, say, an Osprey backpack like the Stratos or Mantra will likely have larger or smaller capacities depending on the size of the backpack.

Posts have mentioned using water and small objects like beads to measure volume, which is true. Some manufacturers have also used sand. Some manufacturers will include the total capacity of a fully filled zipped or fastened compartment, while others only measure the volume up to the zipper or velcro fastener minus the lid.

By and large, we are packing stuff. Stuff that does not compact down as tightly as sand or water. So our looser stuff includes a lot of air as part of the volume that we pack. Depending on the methodology used by a manufacturer, a 40 L measurement may allow more stuff or less stuff to be packed when comparing backpacks.

When I have been hired to gear test a backpack by a manufacturer, I always measure accuracy of size and of capacity based on the size of the backpack I am testing. I have never found a stated capacity measurement to be spot on. Part of this is not just due to methodology of measurement, but also the expected variations introduced because each backpack is being individually sewn and assembled by hand.

I guess from my perspective it boils down to the same basic reason why a size '9' extra wide trail shoe from one manufacturer will fit great, but that same stated size from a different maker will be sheer misery.

 

[Carol06]

I only read this post Dave Bugg in the hope that you would reply. And you did.... you took the hook. It is always great to see your responses. And of course you answered the question. I hope you are well.

 

[Esperanza]

I think of it as somewhat like the measured size of a house. Two houses that are both 1,500 square feet can “live”completely differently, with one feeling cramped and the other spacious. The difference is more than objective square footage; it’s how the space is apportioned, and how it works for your needs.

 

[Camino Chrissy]

The smart money is looking to minimize pack size and weight anyways. Some may consider reduced capacity as a favour to the buyer over a sneaky little rip-off? For me, I’m down to an HONEST, 30L Pack that is so well designed, it can be scrunched up into a pocket pack. (Made by the folks that brought us the Hobo-Roll).

Sounds intriguing...wanna share what it is?

 

[trecile]

Sounds intriguing...wanna share what it is?

I believe that this is the backpack that @MichelleElynHogan is talking about.

30L Free Spirit Travel Backpack

FREE SPIRIT 30L BACKPACK 100% Packable Travel Backpack! And did we mention? It is comfortable too! A truly packable, organizable, travel backpack - perfect for country hopping, day hikes, and ascent day, keep your Free Spirit tucked away until you need it. "LOVE how lightweight and comfortable...

gobi-gear.myshopify.com

 

[Camino Chrissy]

I believe that this is the backpack that @MichelleElynHogan is talking about.

30L Free Spirit Travel Backpack

FREE SPIRIT 30L BACKPACK 100% Packable Travel Backpack! And did we mention? It is comfortable too! A truly packable, organizable, travel backpack - perfect for country hopping, day hikes, and ascent day, keep your Free Spirit tucked away until you need it. "LOVE how lightweight and comfortable...

gobi-gear.myshopify.com

@trecile, thank you...you are often so amazing with your research and help! I appreciate your input.

 

[Geodoc]

Stuff that does not compact down as tightly as sand or water

Uh, DaveBugg, water does not compact (or compress). It can only expand from its liquid state (to solid or gaseous state). Sorry, geonerd here

Having said (written) that, I do believe water would be the best medium for measuring capacity.

 

[davebugg]

Uh, DaveBugg, water does not compact (or compress). It can only expand from its liquid state (to solid or gaseous state). Sorry, geonerd here

Having said (written) that, I do believe water would be the best medium for measuring capacity.

I didn't mean to imply that, clumsy me

I meant that given the state in which water and sand exist in a container, there is not a lot of air making up volume. The stuff we pack, unless vacuum compressed, means it includes a lot of air volume. it is 'fluffier' than air or sand.

Or something like that.

 

[Geodoc]

I knew that. Just messing with a fellow Washingtonian. Hope you're doing well.

 

[MichelleElynHogan]

Sounds intriguing...wanna share what it is?

I have used this pack daily and love it. When I next head out to travel. This is the pack I will be taking, no matter where I go.

30L Free Spirit Travel Backpack

FREE SPIRIT 30L BACKPACK 100% Packable Travel Backpack! And did we mention? It is comfortable too! A truly packable, organizable, travel backpack - perfect for country hopping, day hikes, and ascent day, keep your Free Spirit tucked away until you need it. "LOVE how lightweight and comfortable...

gobi-gear.myshopify.com

 

[Stephan the Painter]

I have used this pack daily and love it. When I next head out to travel. This is the pack I will be taking, no matter where I go.

30L Free Spirit Travel Backpack

FREE SPIRIT 30L BACKPACK 100% Packable Travel Backpack! And did we mention? It is comfortable too! A truly packable, organizable, travel backpack - perfect for country hopping, day hikes, and ascent day, keep your Free Spirit tucked away until you need it. "LOVE how lightweight and comfortable...

gobi-gear.myshopify.com

Looks great. Not expensive either. Have you tried it on a Camino or other through hike?

 

[MichelleElynHogan]

Looks great. Not expensive either. Have you tried it on a Camino or other through hike?

I believe that I answered this question in my last post;

"I have used this pack daily and love it. When I next head out to travel. This is the pack I will be taking, no matter where I go."

 

[trecile]

I believe that I answered this question in my last post;

"I have used this pack daily and love it. When I next head out to travel. This is the pack I will be taking, no matter where I go."

But using a pack in your daily life is not the same as using while walking 6+ hours a day in the Camino or other through hike.

 

[Camino Chrissy]

But using a pack in your daily life is not the same as using while walking 6+ hours a day in the Camino or other through hike.

Those were my thoughts, too, and I was going to reply, but see I no longer need to.

 

[MichelleElynHogan]

But using a pack in your daily life is not the same as using while walking 6+ hours a day in the Camino or other through hike.

Trecile & Camino Chrissy, I guess it is down to trusting my experience or not. I am ok with that. But I do hope that some may consider the possibilities of different thoughts and experiences.

 

[Camino Chrissy]

Trecile & Camino Chrissy, I guess it is down to trusting my experience or not. I am ok with that. But I do hope that some may consider the possibilities of different thoughts and experiences.

Michelle, it looks like a very nice pack and I'm sure it serves you well...no offense was intended.

 

[trecile]

Trecile & Camino Chrissy, I guess it is down to trusting my experience or not. I am ok with that. But I do hope that some may consider the possibilities of different thoughts and experiences.

Michelle, it looks like a very nice pack and I'm sure it serves you well...no offense was intended.

I agree with @Camino Chrissy

 

[kelleymac]

As long as it can carry what you absolutely need and it weighs as little as possible, it doesnt really matter. I've used 5 different packs that were rated at either 40 or 50 litres. They all did well. Just make sure there's always enough room left withought squishing fresh bread, fruit, and vegetables when you can get some.

I always put a baguette on the outside of my pack... well, unless it's raining.

 

[kelleymac]

I didn't mean to imply that, clumsy me

I meant that given the state in which water and sand exist in a container, there is not a lot of air making up volume. The stuff we pack, unless vacuum compressed, means it includes a lot of air volume. it is 'fluffier' than air or sand.

Or something like that.

Good point. It's no help at all to put sand in a compression sack... water either.

 

[Paladina]

My experience of super light backpacks has not been entirely happy. All have been comfortable to wear, but none has survived the rigours of international baggage handling. One went awol on a flight to Ukraine a few years ago, only to reappear with several unexplained abrasions and piercings. But now that I have renewed the annual pledge to go flight-free (easily honoured in 2020-21!) the only holes that are likely to appear are those in my camino calendar. Maybe next year, celebrating an extended holy year with an extensively holed backpack!

 

[colleenbennett]

I read on the Decathlon website only yesterday that they fill the bag with small balls then decant them into a measuring container, how strange this should come up then today

I read that too!

 

[colleenbennett]

Maybe that’s how I ended up with a 20L, a 30L, a 45L and a 50L.

 

[Pilgy]

As long as it can carry what you absolutely need and it weighs as little as possible, it doesnt really matter. I've used 5 different packs that were rated at either 40 or 50 litres. They all did well. Just make sure there's always enough room left withought squishing fresh bread, fruit, and vegetables when you can get some.

Yes. Lots of interest these days in being able to say you have the smallest pack then hanging things on the outside because they do not fit in said pack! I believe Gossamer Gear fills packs with styrofoam beads to measure capacity.

 

[Frank Wortley]

After many years of backpacks I have come to the conclusion that pack manufacturers may all be either drunk or part of a Matrix level conspiracy.

How in the Holiest of Hecks do they determine the Litre capacity of backpacks? I have 28L packs that hold as much as one of my 40L packs in the main compartment. My new 50L actually holds less than my 40L.

I know they supposedly pack every compartment that can be closed with a zip, velcro, or roll and clip and take measurements from there, but sometimes I really think they are just making this stuff up for marketing.

How about just give us the main compartment volume as one metric and accessory space as another??

There. I got it off my chest.

/Rant off; preload/rant2(printerink.arrrg)

M

Yes! How do you know? I have only ever carried a reliable 65L pack and do not worry too much about weight as I train with more than I plan to carry. I this instance I wonder if size matters? Perhaps the disciple of a carefully considered and faithfully followed "what do I really need?" protocol? After that it is take what you are prepared to carry.

 

[Frank Wortley]

Yes! How do you know? I have only ever carried a reliable 65L pack and do not worry too much about weight as I train with more than I plan to carry. I this instance I wonder if size matters? Perhaps the disciple of a carefully considered and faithfully followed "what do I really need?" protocol? After that it is take what you are prepared to carry.

In addition I loose pack anyway. I am often asked how heavy my pack is and am pleased with the smiles as the person picks it up and realises it is about the same as theirs.