By Marcus Hale, Lead Pack Research Editor · Published September 14, 2026, 6:03 PM ET
Direct Answer
Skin-out weight is the total weight of everything you have with you at the trailhead — your pack and its contents, plus every item worn or carried outside the pack, like clothing, boots, trekking poles, and a phone, plus consumables such as food and water. It's the most complete weight number, unlike base weight, which excludes worn items and consumables.
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In plain English
Imagine stepping on a bathroom scale at the trailhead with everything on: your pack, your boots, your jacket, the phone in your pocket and the poles in your hands. Now subtract your own body weight. What is left is your skin-out weight. The name simply means everything from your skin outward.
Hikers use a second number too, called base weight. That is just the gear in your pack, not counting things you eat, drink or burn as stove fuel, because those change from trip to trip. Base weight is handy for comparing tents and sleeping bags. Skin-out weight is handy for knowing how hard your legs will actually work.
You don't need special tools to find it. A luggage scale or a kitchen scale and a simple list are enough. Weigh each item once, write it down, and add up the list before each trip.
Skin-out weight is the total weight of everything you carry and wear on a hike, measured from your skin outward: the backpack and its full contents, plus clothing on your body, boots, trekking poles, a phone or GPS in your pocket, and consumables like food, water, and fuel. It's the number that most accurately reflects what your body actually supports over the course of a hike.
How is skin-out weight different from base weight?
Base weight excludes both consumables and worn or carried items, isolating just the packed gear that doesn't change trip to trip. Skin-out weight includes everything — nothing is excluded. Two hikers with identical base weights can have very different skin-out weights if one wears heavier boots, carries trekking poles, or packs more food for a longer resupply stretch.
Why do some hikers track skin-out weight instead of base weight?
Skin-out weight matters more for understanding total physical load, since your body doesn't distinguish between weight in the pack and weight worn on your feet or carried in your hands — it all adds up to what you're moving over the miles. Base weight is more useful for comparing gear choices between hikers or trips, since it removes variables like food quantity and weather-dependent clothing that aren't really about gear selection.
What typically makes up skin-out weight beyond base weight?
Category
Examples
Worn clothing
Hiking shirt, pants, socks, boots or trail runners
Carried items
Trekking poles, phone, sunglasses
Consumables
Food, water, fuel
Base weight
Pack, shelter, sleep system, cook system, and other packed gear
Skin-out weight is the sum of all four categories, while base weight is only the last one.
How do you calculate skin-out weight?
Weigh your fully loaded pack, then add the weight of everything you're wearing (clothing and boots) and carrying externally (trekking poles, phone), then add the weight of your food, water, and fuel for that specific day or trip. Because consumables and clothing change trip to trip, skin-out weight isn't a fixed number the way base weight is — it's most useful calculated for a specific day, like your heaviest carry right after a resupply.
Where the definitions come from, and where they stop
No standards body defines skin-out weight. It is a hiking-community term, and even base weight rests on definitions from trail groups and gear makers. The Appalachian Trail Conservancy describes base weight as pack weight with all gear, minus consumables such as food, water and fuel.1 Gossamer Gear and Zpacks use the same idea, and Gossamer Gear's widely quoted tiers put lightweight under 20 pounds, ultralight under 10 and superultralight under 5 pounds of base weight.5,2
Notice what those definitions leave unsaid: none of them explicitly addresses the clothes you wear or the poles you hold. Most gear lists treat worn items as outside base weight, which is how this page uses the term, but when you compare your numbers with someone else's, check how they counted. Skin-out weight sidesteps that argument by counting everything.
Why every pound is not equal
A skin-out total treats a pound of boot the same as a pound of trail mix, but your body doesn't. A review of military load-carriage research reports that each kilogram added to the feet raises energy expenditure by roughly 7 to 10%, against about 4% for a kilogram on the thigh, and far less for the same weight on the back.4 That is why swapping heavy boots for lighter footwear can change how a day feels more than the scale suggests.
Weight on the back still counts. In a lab study of walking with a backpack, metabolic energy use rose roughly in a straight line with load, by about 7.6 watts for every extra kilogram.6 The same military review notes that energy cost also climbs with walking speed and grade, so one skin-out total can feel very different on a flat path and a steep climb.4
The consumables swing, in numbers
Water drives most of the day-to-day change. A liter weighs about a kilogram.3 At Guadalupe Mountains National Park, where the NPS asks backpackers to carry a gallon per person per day, that works out to about 8 pounds a gallon and roughly 24 pounds of water for a three-day, two-night trip.7 In a dry desert, water alone can outweigh a lightweight base kit.
The US Army's foot-march doctrine measures loads in a skin-out-like way: its approach-march guideline of about 45% of body weight explicitly includes all clothing and equipment.8 That is a military figure for conditioned soldiers, not a target for hikers, but it shows why a complete total is the honest way to describe what a body is carrying.
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