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What is Skin Out Weight in Backpacking?

What is Skin Out Weight in Backpacking?

Skin Out Weight is the weight of your backpacking gear, water, food, fuel, the clothing you’re wearing, your shoes, watch, sunglasses, smartphone, trekking poles if you use them, and anything else on your person or in your pack. Backpacking Base Weight, in comparison, is your full skin out weight, minus food, fuel, water, and other “consumables” like sun tan lotion, bug dope, toilet paper, and so on.

Most backpackers interested in reducing the weight of their gear spend way too much time trying to minimize their base weight. While this is a useful exercise in teaching you about the different options available, it is largely a waste of time unless you plan on backpacking in a homogenous locale and temperature range, like summer on the Appalachian Trail, where there’s very little variation in the gear you need and ample help is just a phone call away.

But if you plan on expanding your horizons and backpacking across a wider range of destinations, more challenging terrain, or different climates, it makes a lot more sense to focus on your skin out weight, or the range of max and minimum weight you need to carry, in addition to the trip-specific things you need to bring. You just can’t assume that a static gear list is going to be universally suitable for all of your trips.

For example, here are some of the first questions I ask myself when I’m planning a trip:

  • How much water will I need to carry in terms of volume and weight?
  • What is the best shelter for this terrain and climate?
  • How much food do I need to carry?
  • How will I protect my food and smellables from bears and rodents?
  • What is the best water filter in terms of water quality and temperature?
  • What clothing should I bring?
  • What is the best footwear for this trip?
  • How bad will the insects be?
  • Where will I camp?
  • What is the best stove for this locale?
  • Do I need to resupply?

That’s the tip of the iceberg, but the answer to these questions can require big variations in the backpacking gear, clothing, and consumables that you need to carry. I figure out a gear list for each trip I take using different gear combinations from my gear closet, modifying my trip plan if I don’t have the gear required.

Admittedly, there was a time when I did focus exclusively on reducing my backpacking base weight. But when you expand your horizons to include multiple destinations, seasonal variations, or hiking off the grid, Skin Out Weight is a much more relevant metric to optimize than base weight.

For instance, take water. I’m planning a trip now that will require a long water carry with significant elevation gain with a dry camp between water sources. I’ll need to carry six liters of water, which equates to twelve pounds of added load. To do that I need to bring extra reservoirs to hold the water, a backpack that has enough open storage to hold it, and a decent frame to haul the added weight. In other words, my favorite 30L ultralight backpack isn’t going to cut it. That’s just one example.

About the author

Philip Werner has hiked and backpacked over 10,000 miles in the United States and the UK and written over 3000 articles as the founder of, noted for its backpacking gear reviews and hiking FAQs. A devotee of New Hampshire and Maine hiking and backpacking, Philip has hiked all 650+ trails in the White Mountains twice and has completed 12 rounds of the 48 peaks on the White Mountains 4000 footer list with over 576 summits in all four seasons. He is also the author of Backpacking the White Mountain 4000 Footers, a free online guidebook of the best backpacking trips in the White Mountains in New Hampshire and Maine. He lives in New Hampshire. Click here to subscribe to the SectionHiker newsletter.


  1. I learned this the hard way. A spreadsheet is not reality. You learn that quickly when it gets colder or you have to carry water. Stop wasting your money on frameless backpacks. Get one with a lightweight but rigid frame.

    • I have, and am finicky about, a spreadsheet. But it’s only useful as a planning tool: it’s detailed and complete enough that I can predict fairly accurately how much my pack will weigh. If I had more than one pack, it would help me make a decision on which pack to take; since I only have one pack, it lets me determine what changes to make if I exceed the carrying capacity (pounds or liters.) For example, if I decide I’d like to take a 4-day winter trip, I select what goes in the pack (including fuel, food, water, and extra clothing.) If the total exceeds 20 pounds or 45 liters, then I start making decisions: shorten the trip to reduce the food I need, change the location of the trip to a warmer destination so I need less clothing, etc.

      For me, the precise “FSO” weight isn’t that relevant – I know how 20 pounds carries for me in a variety of seasons and terrain, including how various clothing combinations affect that. I don’t carry things in my pockets (lost a really nice knife that way once.)

      But “Base Weight” (and, to some extent, “FSO weight”) is just a backpacker’s version of “Mine’s bigger than yours.”

  2. Here is where PERSONAL experience (lots of trips in differing terrain and various season) is invaluable.

    Someone else’s “dialed in” base weight or total weight is really irrelevant. For example. I’m tall and skinny, need a long bag and sleep cold: I’m using an extra-long -20 bag when you might use a short zero-degree bag. I’m older, so my tarsals, ankles and knees aren’t as resilient as they use to be: I wear an ankle-high boot when you wear trail runners. Sometimes I backpack alone and pare down my kit, but other times I hike with a partner or group and bring along some camping comforts.

    Definitely start with the who/what/when/where/why questions and see how your load out is shaping up. Chat with any hiking mates and see what can be cut. Then let the number fall where they may. Overtime, when you have some spare cash or catch a great sale, swap out some heavy gear for something lighter that performs just as well.

    Spending more time walking or on day hikes to get in shape for a section hike is a better investment of time than researching how you can shave a few grams off your spork. Just load up and get out there. You will still have a good time!

  3. Sooo many things that hikers believe are sooo important are totally irrelevant and useless.

    You need to be able to remove ticks, recognize and stay away from posiounous snakes, know how to bag and hang your food from a tree limb,how to pitch a tent so you don’t get water run off inside,take a BOSO break at least twice a day so your feet don’t turn into hamburger meat!
    If you don’t know what a BOSO is you’re not ready for a thru hike.

    • OK. I don’t claim to be a alpha hiker. I’m satisfied with my 3-day trips and mellow approach. But now you have me curios. What is a BOSO break? I’ve googled it and this is the only place I have ever encountered that term. Thanks for dropping some knowledge.

      • Been hiking for over 40 years and this is the first time I’ve ever heard it. My guess is it means boots off/socks off.

    • This is going to shock you. Many of us don’t want to do a thru-hike.

  4. Just a question about definitions – I have heard skin out weight being “everything but you”, in line with Philip’s definition above, but I have heard base weight as “stuff you carry minus consumables”, but excluding what you wear. That is, base weight does not include your clothes.

    I know people play lighterpack games with what is in their pockets vs. what’s in their pack, and the UltraLightJerk instagram feed sends this up on many occasions.

    Philip’s larger point remains – minimizing base weight is a useful tool towards minimizing total weight, and minimizing total weight should always defer to the risks and needs of a given trip (and to carefully chosen luxury items). The goal is to have fun and stay safe!

    I always take a slightly larger first aid kit than an ultralight backpacker would take because I’m often in a hike leader role, and I want to be the one in an position to help that hiker who needs a bandage or gauze or electrolytes.

  5. I always end up scratching my head about the definition of base weight. I understand the common definition of “Base Weight”, as your backpack with gear, minus food, fuel, water. Where things get really gray for me are items like my cell phone. Is that part of base weight? I carry mine on the shoulder strap of my pack but some folks exclude it. What about my Garmin Inreach mini and my wallet, watch and keys? Are trekking poles included? I guess they are not technically part of my backpack base weight since I carry them in my hands or are they if I carry a trekking pole tent? Anyhow, not to belabor the point but it seems to be quite subjective (especially in youtube 6lb base weight videos ) as to what gets included as base weight. I like Phillips concept of full skin out being everything but me and base weight being skin out weight minus food, water and fuel and other consumbales. Of course since we tend to measure ourselves against others, what is the definition of section hiker base weight to qualify as ultralight? (just being a bit snarky here). I feel that you take what you need for the conditions you are facing as well as what you are willing to carry to enjoy your adventure. THAT is in fact, the optional base weight. Just my 2 cents

  6. From my point of view there is no single metric that rules all others – they just serve different purposes. I typically look at both my base weight and what I call trail weight, which is base weight plus consumables like food, water, and fuel. There are some good points here about the skin out weight which gives a more complete picture of everything including the clothes you are wearing, phone, trekking poles, etc. However, I still think the base weight and trail weight for the pack are useful metrics and shouldn’t be abandoned. I know how much weight my pack can comfortably carry and the shoes on my feet shouldn’t factor into that.

  7. If it fits in your pocket, you don’t need to count it in your base weight.

  8. There is only one weight my feet care about, total moving weight. Gear, food and my body weight. I lost a few pounds and my hike is now much easier.

    • I second that emotion! Getting in good shape for me means leg and foot strength, balance and flexibility. I get honest about my BODY Weight and think hard about how much of this I want to carry up the trail.

  9. BOSO??? I’ve just always called that ‘taking a rest break’

  10. El Diablo Amarillo

    To play devils advocate here the approach myself and some folks prefer is put it in the pack, lace up the boots, and hit the trail. Forget scales, spreadsheets, etc. Take what you think you need or want and if it seems too heavy when you get home either ditch some stuff or train a little harder so the load feels lighter. Quit measuring and fussing over things that arent really important and just enjoy the time spent not working. I can remember as a kid I had a brand new Black Diamond ultralight backpacker dome tent I used for 20 years. It weighed around 7 pounds. An absolute featherweight of a tent compared to what the other scouts in the troop were carrying at the time. Today that weight tent is considered a car camping tent and not even in the backpacking category. . Lesson here is often pack weight is just a matter of perspective and its too easy to mind!+$# things that are just not important.

  11. First time I have seen a definition of base weight that implies it should include worn weight??? That’s not a useful definition imo. Baseweight as I usually see it defined…your pack and its content minus supplies… is useful because it is quick to measure…just weigh your pack and the gear it contains without the supplies…and it instantly gives you the minimum weight you will be carrying, a sanity check on the gear you are planning to take and the “room” you have for supplies (food, water, fuel etc). Plus it provides a normalized starting point to compare with others and learn something. There is no hard rule that says base weight implies a static gear list or must be a specific value or the same for every trip or that it means you don’t also weigh your pack with supplies or care about how much your boots weigh.
    In general carrying less pack weight will improve your hiking performance so lighter is better, other things being equal…the trick is keeping them “equal” or making the right tradeoffs for the trip at hand.
    While I agree with the supporting arguments about gear choices I don’t see skin out weight being any more useful metric than baseweight for getting there…maybe if you are fast packing or doing something competitive…or maybe still wearing jeans backpacking? Actually it seems a lot less useful for most practical purposes since it is harder to measure repeatedly and doesn’t focus on the part of your gear you can easily mix, match, swap or omit items to reduce the load.
    The weight of worn gear, mostly clothing, is not usually the first criteria for its choice. Fit, feel and basic protection from the expected everyday conditions is more important for any reasonable choices. While not insignificant and with the possible exception of footwear, its weight has less effect on your hiking performance than pack weight since it is well distributed. There is grey area with layered clothing as to what is worn and what is carried since that can vary through the day and in changeable conditions. It is just something you have to predict and decide for a particular trip.

  12. Unsurprisingly 6 liters of water will equate to 6kg, just sayin ?

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