It’s a common scene at trailheads everywhere: two hikers comparing base weight numbers, and the lower one usually turns out to be missing something, like a rain jacket, trekking poles, or the stuff sack a quilt lives in, quietly left out because someone “always just thought of those as separate.” Base weight gets treated like a badge, which is exactly why so many people calculate it wrong, whether they mean to or not.
Here’s how to actually do it, what it’s supposed to measure, and why the number alone still doesn’t tell you what you need to know before a trip.
What Actually Counts as Base Weight
Base weight is the weight of everything in your pack except consumables: food, water, and fuel. That’s it. It’s meant to isolate the part of your load that doesn’t change from day to day on a given trip, so you can compare gear choices (and compare your kit to someone else’s) on equal footing.
The confusion almost always comes from what people quietly leave out. To calculate it correctly, weigh:
- The pack itself, empty, on a scale, not estimated from the product page (manufacturer specs are frequently off by an ounce or two).
- Shelter system: tent or tarp, poles if dedicated, stakes, guylines, groundsheet.
- Sleep system: quilt or bag, sleeping pad, pillow if you carry one.
- Cook system: stove, pot, lighter, spork, wind screen.
- Every piece of clothing you’re carrying but not wearing, including extra socks, insulated jacket, rain gear, gloves.
- “Miscellaneous” items: first aid kit, repair kit, headlamp, water filter (the filter itself, not the water inside it), power bank, stuff sacks, trekking pole tips you swapped out.
Notice what’s not on that list: food, water, and fuel. Those are consumables, and they get their own number because they change every single day of a trip and shouldn’t be used to make your gear list look lighter than it is.
The Categories People Conveniently Forget
Worn Weight
Worn weight is what you have on your body when you start hiking: boots or trail runners, socks, base layer, hat, and trekking poles (the one that trips people up), since you’re carrying them in your hands, not in your pack. Worn weight is technically separate from base weight by the strictest definitions, but if you’re comparing your kit to someone else’s total load, leaving it out entirely is how those trailhead arguments start. Trekking pole weight in particular matters more than people expect; I went deep on that specifically in my carbon vs. aluminum comparison.
The Stuff Sacks and Straps You Don’t Think About
Compression sacks, dry bags, the little carabiner you clip your bear spray to, the cord you use as a bear line: none of it is heavy individually, and all of it adds up to real ounces that vanish from most people’s spreadsheets because they never got weighed in the first place.
Base Weight vs. Skin-Out Weight: Which Number to Trust
Base weight is useful for comparing gear systems, but it’s not the whole picture, and serious ultralight hikers increasingly talk about skin-out weight (sometimes called full skin-out or FSO weight) instead. Skin-out weight means everything you’re carrying or wearing except your body: pack, gear, clothing, trekking poles, phone, sunglasses, all of it, still excluding food, water, and fuel.
Skin-out weight is the more honest number if you’re actually trying to understand your total load, because base weight alone lets people hide pounds in “worn” gear that’s just as real on your body as it would be in your pack. If you’re chasing a specific base weight target for its own sake, it’s worth reading the tradeoffs I laid out in my step-by-step base weight reduction guide, but track your skin-out number alongside it so you’re not just moving weight around to hit a number.
How to Actually Weigh Everything Without Losing Your Mind
The old-school method is a kitchen scale, a notebook, and a Saturday afternoon: weigh every item individually, write it in a spreadsheet, total the columns. It works, but it’s tedious enough that most people do it once, let the list go stale, and then have no idea their “10-pound base weight” quietly became 11.5 pounds after three gear swaps over two seasons.
This is honestly the exact problem I built FeatherPack to solve: you photograph each piece of gear, it recognizes what it is and logs the weight, and you build your base weight list once, then just pick items into a trip-specific pack for each hike instead of re-weighing and re-adding everything by hand every time your kit changes. It won’t stop the trailhead arguments, but at least you’ll be arguing with real numbers.
Whichever method you use, weigh gear in the condition you’d actually carry it: stuff sacks on, batteries in, without the cardboard packaging or retail tags still attached.
Common Mistakes That Quietly Inflate or Fake Your Number
- Trusting manufacturer spec weights instead of your actual scale. Brands round down, and “packaged weight” versus “minimum weight” claims can differ by ounces.
- Forgetting trip-specific extras like a bear canister, microspikes, or extra warm layers, then being surprised your pack feels heavier than your spreadsheet says on colder or higher-elevation trips.
- Excluding worn items to make a number look better for a gear list post or a trailhead conversation, which is harmless until you’re the one making buying decisions based on a fake baseline.
- Never re-weighing after a gear swap. Every new stuff sack, replaced item, or “I’ll just also bring this” addition needs to get logged, or your base weight number becomes fiction within a season.
If you want a sense of how far this can be pushed by people actually racing the number down, my thru-hike gear shakedown walks through what a genuinely aggressive sub-5kg kit looks like, and this packing checklist is a good starting point if you’re building your list from scratch rather than auditing an existing one.
Frequently Asked Questions
Does my backpack itself count toward base weight?
Yes. The empty pack is part of base weight, weighed on its own, not estimated. It’s one of the biggest single-item weights in most kits, which is why pack choice gets so much attention in ultralight circles.
Should I count my phone and camera?
If you’re carrying it, it counts toward skin-out weight at minimum. Strict base weight definitions vary on where a phone falls, which is exactly why skin-out weight exists: it removes the ambiguity by including everything except consumables.
Is a lower base weight always better?
Not automatically. A base weight that’s low because you cut essential safety or comfort items for your specific trip and climate isn’t a win, it’s a risk. Base weight is a tool for comparing gear efficiency, not a competition to win regardless of conditions.
How often should I re-weigh my kit?
Any time you swap a piece of gear, and at minimum once per season, since small additions (a new stuff sack, a heavier replacement item, seasonal extras) creep in without anyone noticing until the number is meaningfully wrong.
Getting the number right isn’t about chasing bragging rights, it’s about being able to trust your own data when you’re deciding what to cut, what to upgrade, and what you can actually carry comfortably on the terrain you hike. Do you track base weight, skin-out weight, or just eyeball it and hope for the best? I’d like to hear how you keep your list honest.
