So with switching from traditional backpacking to UL, I've had to buy a lot of stuff. For instance ditching my old rains jacket/pants for some lighter ones. I have a big spreadsheet for my stuff, and when debating a new purchase I compute the weight saved, the cost, and calculate cost per ounce saved. I was wondering if anyone else does this, and if you do, what's your purchase point? Here are some of mine. I feel like at around $3 it's a no brainer, but things like switching to Ti nail pegs ($22 per 1.26 ounce saved) I can't justify it, even switching to thin Ti stakes ($20 for 2.58 ounce saved) I'm not as stoked. Understandably other factors fit into this such as durability and enjoyment, but reality aside, spreadsheet on full bore, what's your cost per ounce threshold for a purchase?

Item Specifics Ounces Other Option Ounces Saved Cost Per ounce
Gaitor OR blue 7.2 Dirty Girl Gaiters 1.1 6.1 $18.90 $3.10

Rain Pants Arc'T 10.2 02 pants 4.15 6 20 $3.33

Rain Jacket Arc'T 13 02 jacket 5.7 7.6 30 $3.95

Backpack Osprey Atmos 61 SMD Swift 27.5 32.5 $180 $5.54

I can use $3 per yard 1.1 ounce nylon from backwoodsdaydreamer or $10 per yard 0.9 ounce from owfinc.com.

2.5 yards = $7.50 or $25 = $17.50 saved

4 square yards = 0.8 extra ounces with 1.1 ounce fabric

$22 per ounce saved

hard to justify that

https://spreadsheets.google.com/spreadsheet/ccc?key=0AqxhyY1jJYrYdGVIaUNmNHFfdmZ6c1VNS0VpU0ltWGc&hl=en_US#gid=0

Calculating such things are fun to do. However, you can easily fool yourself.

Think about this: your weight saving number is better the worse off you were.

For example, going from an 8 lb pack to a 2 lb pack versus going from a 4 lb to a 2 lb. The first one is 3x the second in weight savings. Say the new, lighter pack is $300. So depending on how worse off you were, your wt per oz saved is about $3 or over $9. How is one better? Both cases you end up with 2lb pack for $300.

HIGHER<------------------------>LOWER

we want both cost and
weight to go this way =>

WORSE<----------------------->BETTER

Free things at zero weight are the best while
very expensive and very heavy are the worst

The concept of diminishing returns comes into play as we move from traditional gear to lightweight and then to lighter, and lighter, and lighter...

You begin to consider factors beyond cost. Does it keep me warmer or cooler? Is it simpler to use? Is it comfortable? etc

IMO, calculating savings per oz is just a way for us to rationalize an irrational purchase : )

I do this analysis when contemplating more expensive purchases. It doesn't require a spreadsheet, just simple math. You take the difference in weight between the old item and the new item, subtract the probably selling price of the old item, then divide that result by the number of ounces saved.

I have saved myself quite a few $$$ doing this simple calculation. Of course, there's the subjective element, too. If it's something I really want anyway, rather than just a weight saving, I'll probably get it anyway. I've learned the hard way (after some very uncomfortable nights) about buying something only because it weighs less!

When I was first going ultralight, I dropped a lot of cash and shaved a ton of pounds. My baseweight used to be around 30-35 lbs, now it's under 10 (under 7 if I'm going fast and light). Since my load is already so comfortable, I don't feel a need to buy much anymore. Saving a couple ounces by spending a ton on a Cuben shelter just isn't my thing. However, if I can improve my efficiency or comfort without a weight penalty, that can be worth it.

I just purhcased a Montbell Thermawrap (used). It's about the same weight as my current insulation layer, but warmer. $100 for a lots of extra comfort is well worth it to me. I also just "purchased" a Back Country Boiler. Weight savings will be nonexistent on an overnighter, but the faster burning time combined with the ease of use, cold weather capabilities, and flexibility is well worth the $90. Plus, it'll make for huge weight savings on longer trips.

However, for pure weight savings, I can't see myself spending much more than 5-8 bucks per ounce right now. Beyond that just seems silly.

Does your spreadsheet add money when you swap say an expensive stove for one made of an aluminum can you got out of the recycle bin? Or when you stop carrying 6 ounces of toothpaste and instead start carrying .5 ounces?

While you are learning about the cranking of numbers, also really pay attention when the subject of financial planning is taught. For example...

Biff Numskul wants to reduce his pack weight. He has a credit card, but does not like the idea of paying all that interest for gear. He decides to plan where he wants to go with his gear weight, and then save and buy over a year to achieve his results.

======== Current ======= Target ===========
oz lb oz lb
shelter 80 5 16 1
pad 48 3 14 0.875
bag 56 3.5 24 1.5
pack 120 7.5 8 0.5
total 304 19 62 3.875

NO MORE THAN $1000 over a year...

To do this Biff plans to save $80 per month

mo====== saved=== spend=== remaining== action
2 160 160 0 buy pack
6 480 280 40 buy quilt
8 640 140 60 buy pad
11 880 300 0 buy shelter

Then for those four items, Biff dropped from 19 lb to < 4 lb over a year and spent < $1000

If you do this:
A year from now, you will have a lighter pack and also will not incur debt to do so
Light load on your back and no debt on your back - good simple living : )

I was just curious what people's individual thresholds were.


I definitely didn't even THINK to calculate re-sale values into the equation, thanks Eric.

George you're absolutely right, it's much more "economical" in my spreadsheet to move from old heavy things to light ones. But that's kind of my point. Is it worth it to upgrade my fancy down sleeping bag to a quilt? Maybe, but I want to prove that to myself with hard facts rather than "oooh look!". It's totally not a bombproof system, but I think calculating it out is an important part of a decision making system. I fully agree with you on the debt thing. As a college debt paid off graduate, I can tell you I used to calculate how many beers per month my debt was accumulating in interest, and by paying X off, how many beers I'd gain.

Mary my spreadsheet IS my simple calculation =). I work in computers. Plus with my awful memory my file is less likely to be lost than the slip of paper, and I can keep track of everything, not do so selectively. It's cheaper to save 3 ounces on your sleeping undies than it is your tarp, but underwear just isn't as shiny, so I think people tend to ignore it for "upgrades" (okay I officially feel silly saying that).

Nate that's about where I'm at too.

Piper: no it definitely doesn't. Good point! It'd be cool to work in something like that for the "yay!" kind of factor.

It's not very often that the decision is as simple as 'Do I want to spend X dollars to save this much weight?'. Usually there are a bunch of other considerations as well pertaining to the function, quality and usefulness of the item. With your rain gear example, the lighter rain gear is also likely to be less durable and it may be lacking features that your current one has. So the complete question may be "Do I want to spend X dollars and give up some durability and a few pockets to save Y ounces?". It's important to consider all the differences when deciding rather than getting starstruck at the ounces that can be saved. Saving weight is amazing, but you need to fully consider what you're getting into. I know I've wound up disappointed with a few pieces of gear when the expensive new UL item didn't work quite as well as it's predecessor.

For me, if it is a situation where there are no downsides to the lighter piece of gear other than the price, then I'll spend quite a bit (ie. $30/oz). I love situations where I can save weight just by spending money because it means I can be just as well equipped on the trail, yet lighter. A good example of this is down quality. I will happily spend extra money to get the best down I can, because the only downside is the price. An extra $100 to get 850 or 900 fp down means years of having a lighter and smaller packing sleeping bag with no cons aside from the initial purchase price. Conversely, some weight savings purchases continue to affect you on the trail. Often it's through lower durability, but it could also be in function (ie. carbon poles are more flimsy, some lighter tent floors are less waterproof).

Another aspect to good gear decisions is considering how your gear arsenal might change down the road. It you can't afford the best sleeping bag, should you buy a decent one now and then perhaps replace it in a year or two with a really good one? Or just wait a bit longer and buy the best now? Usually it's far more economical to just buy the best gear from the start, then it is to evolve in that direction by buying and selling many times. If you currently own a 600fp down sleeping bag, the cost per ounce to upgrade to a 700fp sleeping bag may be lower than an 800fp bag, but if you buy the 700fp bag you will either have to live with those ounces for years or upgrade again to the better bag and that will cost you even more than if you just bought the good one from the start. The bottom line for me is that I buy the best (within reason) and if I can't afford it then I buy fewer pieces of gear. I'd rather replace one or two pieces of gear per year with really good ones, rather than replace a lot of gear with more okay gear. With this approach, I will eventually have a full set of very good gear, rather than an evolving set of mediocre gear.

Edited by dandydan on 05/25/2011 23:40:26 MDT.

Dan - excellent post.

You said: I love situations where I can save weight just by spending money because it means I can be just as well equipped on the trail, yet lighter.

I agree and like that! That's great advice for those beginning their light bp journey.

In the beginning I leaned more toward the $ and wt, but consider the "COMPLETE DECISION" now like you.

Well said Dan. I'm in agreement on the buy quality once method. I think it gets a little tricky though if you're trying to shed weight and don't fully know what you're giving up in a lighter, "higher quality" item versus your current item (say going from a cheapo synthetic mummy bag to a nice down quilt). Despite thorough research (i.e. getting user feedback, etc), sometimes it's hard to find out an item's deficiencies for you in the place you frequent without using it.

To Michael's OP, I try to look at both $/oz and the % of weight savings. I don't know that I would buy a $3 item that saved 1 oz off a 10 oz item just because it was at the $3/oz threshold. I would buy an item that cost $80 and saved me 8oz on a 10 oz item ($10/oz). In one case, my weight savings is only 10% in the other 80% even though the $/oz was more. The lower the items weight, the higher the percentage has to be for it to be worth it for me.

Michael, as an accountant (now retired, thank goodness) I'm most definitely a spreadsheet person, too--I couldn't survive without it! I just wanted to point out that a spreadsheet isn't necessary for these calculations. Not everyone is into computer spreadsheets!

I basically justify buying new gear as the following:

Best value is bought immediately to fill gear gaps unless I my budget can afford the best value. If I'm replacing gear, I just save up until I can afford the best performance item/material. It helps to not need instant gratification.

I'll sell/give away the old gear if I will NEVER use it again. I will keep the old gear and use it as loaner gear so that I can take my less dedicated but enthusiastic friends LW/UL/SUL backpacking with me. Their rental cost is paid in me grinning at them wishing they had an even lighter load like my own at the end of a day.

Other than that I don't pay much attention cost/oz. If my budget situation allows for it, I'll buy a new piece of gear. I also tend to buy the best gear (in my opinion based off several factors from experience) regardless of price. If I can't afford it now, I'll wait until I find I great sale or save up the money to buy it. If I need a piece of kit immediately to fill a gear hole (like a tarp was lost and now you need to get a new shelter ASAP) I'll usually buy the best value I can (like a $4.50 blue tarp @ 12oz) and then save up to replace with the best performance (like a $250 cuben tarp @ 4 oz although making one is more my style and saves the $$$).