Backpack Volume vs Base Weight: Litres by Trip Length
Pack volume follows nights on trail, then base weight decides where in the range you land: for one night the brands run 35–50 L, for four nights 42–70 L.
What each brand says
| Trip | Gregory |
|---|---|
| Day Hike (1/2 - 1 Day) | 15–25 L |
| Full-Day Hike / Winter Day | 20–35 L |
| Weekend Trip (1 - 3 Nights) | 35–50 L |
| Multi-Day Hike (3 - 5 Nights) | 50–70 L |
| Multi-Day Hike Remote | 60–100 L |
Osprey describes trips in words ("a 35-40 L pack suits a single overnight stay") and sells by category: Day Hiking Packs 5–19 L, Weekend Packs 20–39 L, Multi-Day Hikes 40–59 L, Extended Treks 60–79 L, Expedition Packs 80+ L. Gossamer Gear names a trip length for each of its packs, from 28 L ultralight overnights to 60 L for 7+ days.
Base weight
Base weight is everything in the pack except food, water and fuel. Gossamer Gear frames the choice as a question: "Is my base weight under 15 pounds or closer to 25?" and adds: "When your gear is dialed in, 40 to 42 liters is more than enough for multi-day adventures." Compact quilts, a light shelter and a small stove are what let a hiker sit at the bottom of the range; a bulky bag, a four-season tent or a bear canister push to the top. In winter Gregory adds 10 to 15 litres.
Worked examples
- One night: Osprey 35–40 L; Gregory 35–50 L; Gossamer Gear 28 L; Gossamer Gear 36 L; Gossamer Gear 38 L; Gossamer Gear 42 L. One-night page.
- Four nights: Gregory 50–70 L; Gossamer Gear 42 L; Gossamer Gear 50 L. Four-night page.
All trip lengths are on the backpack size hub, and the profile tool adds a pack to your other gear.
Sources
- Osprey backpack size guide, checked 2026-10-20
- How to choose the perfect hiking backpack, checked 2026-10-20
- What size backpack do I need for backpacking? (11 Mar 2026), checked 2026-10-20
Questions
What size backpack for a weekend?
Read the one- and two-night rows: Osprey, Gregory and Gossamer Gear each publish a litre figure, and the worked examples above show where they land.
How much bigger should a winter pack be?
Gregory says to plan for additional litres for winter gear; the figure is in the base weight section.