Choosing the Right Backpack Volume (Without Overthinking It)

April 26, 2026

There’s a quiet truth about backpack size that most people only learn the hard way:

Bigger isn’t better, it’s just easier to overpack.

Choosing the right volume isn’t about chasing numbers; it’s about understanding what you actually carry, how you pack, how you move, and where you're headed.

Start With This: What Are You Actually Carrying?

Before you look at litres, look at your gear reality.

A weekend hut hike is not the same as a multi-day traverse.
A shared tent is not the same as going solo.
An inflatable mattress packs differently to a foam pad.

The most grounded way to figure this out is simple:

Gather your base gear (everything except food and water)
Pack it tightly into a box
Measure the volume (volume (L) = length x height x width / 1000)

That number is your true baseline; not a guess, not a marketing spec, but your actual kit in real space.

From there, you build up.

Add What Changes: Food and Water

Food is the biggest variable.

A useful rule:

1.2 to 1.8 litres of food per day

So if your longest trip is five days, you’re adding roughly:

6 to 9 litres of food volume

Water depends on your setup:

Bottle pockets; don’t count it, as generally side pockets aren't included in the quoted volume of a pack
Hydration bladder; include it in your volume

Now you’ve got a realistic total; grounded in how you actually hike.

The Part Most People Get Wrong

Once you have your number, the instinct is to size up.

That’s where things go sideways.

A pack that’s too big doesn’t just leave empty space, it loses structure.
And when a pack loses structure, it loses comfort.

A tightly packed bag carries better; it holds its shape, it moves with you.

That’s why ultralight packs tend to run smaller:

They encourage you to pack intentionally
They compress properly
They stay comfortable under load

A full small pack carries better than a half-empty big one.

The Reality Check (Keep This Simple)

If you ignore everything else, keep this:

Day hikes: 20–30L
Weekend (1–3 nights): 40–50L
Multi-day (3–5 nights): 50–65L

That’s where most hikers land; not because it’s a rule, but because it works.

For most setups, something like the Oryx 44L sits comfortably in that weekend to light multi-day range, while the Oryx 52L gives you a bit more margin for longer food carries or colder conditions without stepping into overbuilt territory.

Why Smaller Often Wins

Going slightly smaller does two important things:

It forces clarity
You take what you need, not what might be nice
It improves carry comfort
A packed bag is stable; an empty one collapses

There’s also more flexibility than people think:

External pockets
Front mesh
Shock cord storage

Ultralight packs are intentionally simple inside; no internal dividers, no unnecessary compartments. That’s where a system like ultralight colour-coded compression stuff sacks comes into its own. Using a mix of large and small sacks lets you organise your kit cleanly while still packing tightly and efficiently.

Bulky, low-risk items can live outside the main pack; things like rain gear or quick-access layers can be stored in outer bungee lacing; removable shoulder strap or hip belt pockets are great for keeping essentials close without eating into your main volume.