Key takeaways
- Pack volume is a backpack's capacity in liters — how much gear it holds.
- It's the main way packs are sized: daypack ~15–30L, overnight 30–50L, multi-day 50–70L, expedition 70L+.
- Match volume to trip length, gear bulk, and how light your kit is.
- Aim for big enough without oversizing — an oversized pack invites overpacking and dead weight.
What pack volume is
Pack volume is the carrying capacity of a backpack, measured in liters — the total amount of gear it can hold. It’s the primary way backpacks are sized, with bigger numbers meaning more capacity.
Choosing the right size
- ~15–30L — daypacks for day hikes.
- 30–50L — overnight or fast-and-light trips.
- 50–70L — typical multi-day backpacking.
- 70L+ — winter and expedition loads.
Match volume to your trip length and gear bulk — and note that lighter, more compact gear lets you carry a smaller volume for the same trip.
A backpacker who’s trimmed their base weight with compact ultralight gear fits a three-day trip’s kit into a 45L pack — where a traditional setup would have needed 65L — carrying a smaller, lighter pack as a result.
Don’t oversize
A bigger pack isn’t better: an oversized pack adds weight and tempts you to overpack, filling the extra space with gear you’ll then have to carry. Aim for a volume that’s just big enough for your typical load — a snug fit beats a cavernous one.
The bottom line
Pack volume is a backpack's capacity in liters — the main way packs are sized, from ~15–30L daypacks to 70L+ expedition packs. Choose by matching volume to your trip length and gear bulk, and remember lighter gear needs less volume. Aim for just big enough: an oversized pack only adds weight and tempts you to overpack.
Frequently asked questions
What is pack volume?
Pack volume is the carrying capacity of a backpack, measured in liters — essentially how much gear the pack can hold. It's the primary specification used to size backpacks, with bigger numbers meaning more capacity. A 20-liter pack is a small daypack; a 65-liter pack is a multi-day backpacking pack.
What pack volume do I need?
Match it to your trip and gear: roughly 15–30L for day hikes, 30–50L for overnight or fast-and-light trips, 50–70L for typical multi-day backpacking, and 70L+ for winter or expedition loads. Lighter, more compact gear lets you carry a smaller volume for the same trip length, so ultralight backpackers use smaller packs than the trip would traditionally require.
Is a bigger pack always better?
No. An oversized pack adds unnecessary weight and tempts you to overpack and fill the extra space with gear you don't need (and then carry). Aim for a volume that's just big enough for your typical load. It's better to have a pack that fits your kit snugly than a cavernous one that's mostly empty or stuffed with excess.
Sources
- Choosing a backpack — American Hiking Society
- Pack systems & fit — The Mountaineers