Total Weight of backpack

I've been backpacking and climbing longer than i care to remember. I am not an Ultralight guy, but I appreciate the manufacturers making lighter gear and i have reduced my pack from 50 lbs in the early days to half that now. I am a bit mathematically inclined and wanted to come up with a definitive way to evaluate my pack weight, or any person's pack weight and here is what i came up with. I haven't seen this anywhere else. I like a % of body wt estimates, but what about overweight people, they would not exert the same effort as a fit person with the same % Body Wt. pack. So here is my idea. You take your height and calculate your Wt. at BMI 25. (calculators and charts are available on line) Then you take 15% of that and that will be a reasonable weight (but not UL). Then you take 20% of the weight at 25% BMI and that tells you what most people will carry on a multi day trip. Then you take 20% of that ideal body weight and that will be more than any reasonable person would enjoy hiking with: Too much by far. Of course elevation gain, distance and fitness are also factors, but for me and the people I hike with my little formula seems to work well. here is a chart of how it works. the column headings are out of line, but you get the idea. height, h squared, div by 28.12 then the three columns of good, okay, not okay; weights in pounds. (none are Ultralight wts and include food and a liter of water).

Height h^2 h^2/28.12 15.0% 20.0% 25.0%

54 2916 103.7 15.6 20.7 25.9
55 3025 107.6 16.1 21.5 26.9
56 3136 111.5 16.7 22.3 27.9
57 3249 115.5 17.3 23.1 28.9
58 3364 119.6 17.9 23.9 29.9
59 3481 123.8 18.6 24.8 30.9
60 3600 128.0 19.2 25.6 32.0
61 3721 132.3 19.8 26.5 33.1
62 3844 136.7 20.5 27.3 34.2
63 3969 141.1 21.2 28.2 35.3
64 4096 145.7 21.8 29.1 36.4
65 4225 150.2 22.5 30.0 37.6
66 4356 154.9 23.2 31.0 38.7
67 4489 159.6 23.9 31.9 39.9
68 4624 164.4 24.7 32.9 41.1
69 4761 169.3 25.4 33.9 42.3
70 4900 174.3 26.1 34.9 43.6
71 5041 179.3 26.9 35.9 44.8
72 5184 184.4 27.7 36.9 46.1
73 5329 189.5 28.4 37.9 47.4
74 5476 194.7 29.2 38.9 48.7
75 5625 200.0 30.0 40.0 50.0
76 5776 205.4 30.8 41.1 51.4
77 5929 210.8 31.6 42.2 52.7
78 6084 216.4 32.5 43.3 54.1


Jim

I am a bit confused. You include food and then only refer to "multi-day". That is a lot of variation! An overnight trip is a lot lighter than a 14-day trip. Are your three pack weights then reflective of the added food for a longer trip? By the way, my BMI is 18. Where does that put me?

And if what is "good" is defined as what "any reasonable person would enjoy hiking with", I must be quite an unreasonable person!

I question the concept that height is the key factor in strength or comfort range in what you carry. Smaller people always will be carrying a larger percent of their ideal body weight simply because certain things, like a tent, weigh the same whether you are five feet tall or 6 feet tall. Clothing is proportional, but some of the other big items are not.

You should carry what you need, not be miserable all the time an strive to figure out how to go lighter when you can. But I must say that on longer trips, I can count on a bit of misery until I get some of that food eaten.

But anyway, interesting table you have there.

I think you should also account for the weight of an individual's body fat and lower what's reasonable for them to carry the higher that is. My reasoning is that given two people of equal height, muscle mass, and pack weight, but with person A at a low BMI and person B at a high BMI, person B is working much harder.

You have me carrying 35 lbs., but there's no way I could carry that much. 20-25 lbs. total pack weight is more like it for me.

The table is very confusing--it's pretty hard to set up any kind of a table in forum software, so that's not your fault! Its main problem is that it takes no account of individual differences, such as a bum knee. There are also differences between males and female height/weight tables that aren't accounted for. The BMI is also an arbitrary sort of number, based on height/weight tables, that doesn't take into account whether a person is pudgy or muscular (muscle tissue being far more dense, the BMI is higher for a muscular person than a pudgy person). The muscular person appears overweight according to the BMI, but is not.

Interesting concept, though!

I'm kinda glad that I am not the only one that does not understand the math there. I think I understand Einstein's theory of general relativity better than the OP's carry weight equation.

I agree with what you said. Trying to find universal truths is an old method of scientific reasoning. Nowadays the trend is too look more closely at individual differences. So I suppose there is no "theory of everything" and individuals need to just record how the feel with different pack weights,on hikes of various elevation gains and distances.

I find the table interesting just from a general guidelines type perspective. I didn't scrutinize the math that much but when I look at the line for my height the pack weights listed are kind of what I would have expected based on long ago past experience. And that is where my current gear inventory comes from--at least 15 years ago.

What I am curious about is how often do people really weigh their packs? Once you have the gear you are happy with and know what it weighs then what more do you need to know? You pack what you need for the hike at hand and off yu go. Do people really stress out over every ounce on every trip?

I have been evaluating the gear I have in an effort to see where I might do some weight reduction as funds become available. But I loaded up my pack with my current gear and went for a couple of test hikes locally. I could not tell any difference when I added something that increased pack weight by almost 3 pounds. Now I realize I might notice it more on a multi day hike but pack weight is going to vary from hike to hike I would think. And yet I see people trying to decide how best to lose an ounce or two.

Maybe I am just out of touch for so long that I don't get it. I have always tried to keep pack weight down but have never obsessed over it like some of what I am reading. But then again I have never been in a position to do thru hikes of a really long trail and so far, thankfully, do not have to deal with any serious physical difficulties.

I could not tell any difference when I added something that increased pack weight by almost 3 pounds.

Well, the lesson there might be that you aren't very good at estimating weight.

In real terms, carrying an extra 3 pounds does not add much to your body's work load in terms of a percentage increase. And if you aren't walking very far or up a very steep incline, you aren't likely to notice much difference at first. Where it adds up is the cumulative difference over a full day of hiking, with the force and stress of those 3 extra pounds added to each step over more than 15,000 steps (assuming you hike about 9 or 10 miles).

Your table says the only factor in the weight of your pack is your height, when we all know there is a lot more to it than that.

Here's my equation: Take backpack + Gears+ Food/Water= Total weight. Are you uncomfortable? Start subtracting from the above equation.

+100! That is the most sensible pack weight formula I have read on any of these forums. If you have what you need and need what you have and the weight feels good to you then go hike.

Jim
Some time a go I wrote something about this. My equations calculated the body muscle mass, determined from that how much could be carried at 0% body fat, and then subtracted the weight of the body fat. so it was a pound of muscle per pound of load thing. Seem to recall a number like 6 pounds of load per pound of muscle, but then who has accurate enough information about their body to enter real numbers?

I would not include height.

So me as an example.
About 10% body fat, weight 170 (rounded for ease of calculation).
So I have about 17 pounds of body fat. Say I am 20% muscle (maybe a tad high?), 0r 34 pounds muscle. 34 pounds x 6=192. 192-170 = 22 pounds, minus 17 pounds of fat means I can carry a 5 pound pack - so much for calculations.
Jim

Quote:

"I could not tell any difference when I added something that increased pack weight by almost 3 pounds."

Piling on to this comment ... If my base weight were 25 pounds, I likely wouldn't notice a 3 pound addition. My base weight is, however, typically in the range of 13 to 15 pounds. So three pounds for me is at least a 20% weight increase (okay, true, not including food or water).

Just earlier this month, doing two to four-day resupplies on the Florida trail I added weights in this range each time. And I very definitely felt it (and this on a trail with very very little uphill). So the lighter your base weight, the bigger the impact from consumables. But taking weight off your base weight is even more profound as that's just "always gone". After a couple of weeks on the trail, walking into a trail town with almost no water and food, I really don't even think about the fact that I'm wearing a pack.


I'm sure there's a lot of variation in this, but something pretty easy to do is to keep a spring scale in your car and just get in the habit of weighing the "just as I'll actually be carrying it" pack just before you start a hike. Maybe even pause to temporarily take out food, water, and fuel if you want a hasty base weight too. Doing this on a regular basis takes little time and helps mentally calibrate how much you're carrying with how it feels on your back.

For my part, I've got a spreadsheet and for any trip of significant length I just put the pieces together with the weights already in there. The longer and/or tougher the trip the more I might cogitate over gear choices to tune things a little better. With experience and a consistent process this needn't be a long and elaborate thing, and for me at least, it makes a very big difference in long term health, energy, and happiness over a trip.

For just a trip of a few days, however, I'm more cavalier.