Base weight, explained: the one number that changes how you pack
If you spend any time around lighter-pack hikers you’ll hear one number thrown around like a badge: base weight. People quote it the way runners quote a marathon time. So what actually is it, and why does it matter more than the number on your bathroom scale with the pack on?
The definition
Base weight is the weight of everything in your pack except the things you consume or wear. Concretely:
- Base weight: pack, shelter, sleep system, cook kit, layers you’re not wearing, the stuff that’s the same on day one and day five.
- Consumables: food, water, fuel. These shrink as you walk, so they’re counted separately.
- Worn weight: shoes, the shirt on your back, trekking poles in your hands. On your body, not in your pack.
Add all three and you get total pack weight. But base weight is the one people obsess over, because it’s the part you actually control with gear choices, and it doesn’t change with trip length.
Why base weight is the honest number
A three-day trip and a ten-day trip can have wildly different total weights and identical base weights. Food and water are a function ofhow long, not how smart. Base weight strips those out so you can compare your setup to someone else’s, or to your own last season, fairly.
The rough cultural mile-markers, for a three-season kit:
- Under ~9 kg (20 lb): traditional, comfortable, nothing to apologize for.
- Under ~4.5 kg (10 lb): “ultralight,” the classic threshold.
- Under ~2.3 kg (5 lb): “super ultralight,” usually a deliberate, dialed, slightly obsessive setup.
These aren’t goals handed down from on high. They’re just useful fences. Comfort, safety, and the conditions you’re walking into always win over hitting a round number.
The trap
Base weight is a means, not the point. It’s easy to shave 200 grams off your sleep system and then carry three extra liters of water you didn’t need to, or leave the rain layer that keeps you alive. Chase base weight to notice what you carry, not to win an argument on the internet.
How to actually find yours
Weigh each item once (a cheap kitchen scale is plenty) and record it. That’s the tedious part, and it’s exactly the part packbook is built to make painless: scan an item, it gets identified and weighed, and your base weight adds itself up on every list. When you can see the number move as you swap gear in and out, packing lighter stops being a chore and starts being a game.
Curious what real setups look like? The explore shelf is full of published packs with their base weight right on the card.