How to Choose the Right Backpacking Pack Size

Choosing the right backpacking pack size can make or break your trip.

Too small, and you’ll struggle to fit essential gear. Too large, and you’ll end up carrying unnecessary weight that drains your energy mile after mile.

Many beginners believe that backpack size is primarily about storage space. It’s not. Comfort, trip length, packing style, weather, and even your experience level all play a role.

If you’ve been searching for how to choose backpacking pack size, this guide will help you understand exactly what matters and what doesn’t. No complicated jargon. No overhyped advice. Just practical information that actually helps.

By the end, you’ll know:

• What backpack sizes really mean

• How trip length affects pack choice

• What beginners usually get wrong

• How to choose a pack that feels comfortable instead of frustrating

Let’s start with the most important thing first.

Backpack Size Is About Volume, Not Physical Size

When backpacking packs are labelled:

• 40L

• 55L

• 65L

The “L” stands for litres, which measures carrying capacity.

It does not mean:

• Bigger person = bigger pack

• Smaller person = smaller pack

This confuses a lot of people at first.

A backpack’s volume tells you how much gear it can carry, while the fit determines whether it’s comfortable on your body.

Those are two completely different things.

Why Choosing the Right Backpacking Pack Size Matters

The wrong pack size affects more than convenience.

It impacts:

• Comfort

• Energy levels

• Balance

• Organization

• Hiking performance

I’ve seen beginners buy oversized packs, thinking:
“More space is safer.”

Usually, the opposite happens.

Extra space encourages overpacking. Then suddenly you’re carrying heavy items you never actually use.

And trust me, unnecessary weight feels a lot heavier after a few hours on the trail.

The Most Common Backpacking Pack Sizes Explained

Here’s a simple breakdown most beginners can follow.

This isn’t a strict rule, but it’s a solid starting point.

How Trip Length Affects Backpack Size

Trip duration is one of the biggest factors when learning how to choose backpacking pack size.

The longer the trip, the more gear and food you’ll need.

But longer trips do not automatically mean massive backpacks.

Smart packing matters too.

Overnight Backpacking Trips

For 1–2 nights:

• Most people do well with 40–50L packs

This gives enough room for:

• Shelter

• Sleep system

• Food

• Extra clothing

Without becoming bulky.

For beginners, this range is usually the sweet spot.

Multi-Day Backpacking Trips

For 3–5 days:

• 50–65L packs become more practical

You’ll likely carry:

• More food

• Additional layers

• Extra water capacity

Especially if weather conditions vary.

Extended or Winter Trips

Longer or colder trips require:

• Bulkier sleeping bags

• Heavier insulation

• More equipment

That’s when 65L+ packs start making sense.

Winter gear takes up surprising amounts of space.

Backpack Fit Is More Important Than Backpack Size

This might sound strange, but:

A properly fitted pack matters more than a few extra litres.

A backpack can be the perfect volume and still feel terrible if it doesn’t fit your body correctly.

Understanding Torso Length

Most beginners assume backpacks are sized by height.

They’re not.

Backpacking packs are fitted based on:

• Torso length

• Hip fit

Your torso length is the distance between:

• The base of your neck

• The top of your hips

This determines how the pack distributes weight.

Why Hip Support Matters So Much

A good backpack transfers most of the load onto your hips, not your shoulders.

That’s critical.

Without proper support:

• Shoulders fatigue quickly

• Neck strain increases

• Hiking becomes miserable

A well-fitted hip belt should carry most of the pack’s weight comfortably.

How Your Gear Setup Changes Backpack Size Needs

Not all backpackers pack the same way.

Some people carry:

• Ultralight gear

• Compact sleep systems

• Minimal clothing

Others prefer:

• More comfort

• Larger shelters

• Extra layers

Neither approach is wrong.

But your gear setup directly affects the pack size you’ll need.

Ultralight Backpacking vs Traditional Backpacking

This is one of the biggest differences in pack selection.

Ultralight Backpackers

Usually carry:

• Smaller packs

• Minimal gear

• Lightweight equipment

They prioritize efficiency above comfort.

Traditional Backpackers

Usually carry:

• More comfort items

• Larger sleep systems

• More backup gear

This often requires larger packs.

Honestly, beginners usually fall somewhere in the middle—and that’s perfectly fine.

Common Beginner Mistakes When Choosing Backpacking Pack Size

Learning how to choose backpacking pack size becomes much easier when you know what mistakes to avoid.

Choosing a Pack That’s Too Large

This is probably the most common mistake.

People think:
“I’ll have extra room just in case.”

But extra room usually becomes:

• Extra clothes

• Extra gear

• Extra weight

A smaller pack naturally encourages smarter packing.

Ignoring Weight Distribution

Some backpacks technically fit your gear, but carry weight poorly.

That creates:

• Shoulder strain

• Lower back discomfort

• Poor balance

Comfort matters more than squeezing in extra items.

Buying the Pack Before the Gear

This one surprises many beginners.

Ideally, you should know:

• Your shelter size

• Sleep system bulk

• Clothing needs

Before finalising the pack size.

Gear volume affects everything.

How Weather Conditions Affect Backpack Size

Weather changes packing requirements dramatically.

Warm Weather Backpacking

Usually requires:

• Lighter sleeping bags

• Fewer layers

• Less bulky gear

This allows smaller packs.

Cold Weather Backpacking

Requires:

• Insulated clothing

• Larger sleeping bags

• More food

• Extra protection

Cold-weather setups take up much more space. 

Your sleeping bag is one of the bulkiest items in any backpacking setup, so it’s worth looking at how modern compact sleeping bags are designed for backpackers. Have a look at one of the compact sleeping bags on Amazon here.

How to Test Whether a Backpack Size Works for You

A backpack can look perfect online and still feel awful in real life.

Testing matters.

Load the Pack Properly

Don’t test an empty backpack.

Add realistic weight:

• Water bottles

• Clothes

• Camping gear

A loaded pack feels completely different.

Walk Around for More Than Five Minutes

Seriously.

A backpack may feel fine initially, then become uncomfortable quickly.

Pay attention to:

• Shoulder pressure

• Hip discomfort

• Balance

• Movement restriction

Features That Actually Matter in a Backpacking Pack

Some features genuinely help.

Others are mostly marketing.

Here’s what matters most.

Adjustable Hip Belt

Essential for comfort and load transfer.

Ventilation

Back sweat is unavoidable, but good airflow helps.

Especially in warm weather.

Accessible Storage

Quick access pockets for:

• Water

• Snacks

• Navigation tools

Make hiking smoother.

Compression Straps

These help stabilize loads when the pack isn’t full.

Very underrated feature.

Do Beginners Need Large Backpacking Packs?

Usually, no.

In fact, beginners often enjoy trips more with slightly smaller packs because:

• Less weight

• Simpler packing

• Less clutter

For most beginner backpackers:

50–55L is often the ideal starting range.

Large enough for comfort.
Small enough to avoid overpacking.

Backpack Weight vs Pack Capacity

Bigger packs often weigh more themselves.

That means:

• More fabric

• Larger frames

• More features

Sometimes people focus only on storage space and forget that the backpack itself adds weight too.

Every kilogram matters eventually.

Internal Frame vs Frameless Packs

You’ll probably encounter both while researching how to choose backpacking pack size.

Internal Frame Packs

Most beginners should start here.

Benefits:

• Better weight distribution

• More support

• More comfort

Especially for heavier loads.

If you’re unsure what an internal frame backpack actually looks like, here is an example of an ultralight backpack on Amazon commonly used for beginner backpacking trips.

Frameless Packs

Usually used by experienced ultralight hikers.

They:

• Save weight

• Require efficient packing

• Works best with lighter gear loads

Not ideal for most beginners.

How to Pack Efficiently Regardless of Backpack Size

Even the perfect backpack feels bad if packed poorly.

Keep Heavy Items Close to Your Back

This improves:

• Stability

• Balance

• Comfort

Store Frequently Used Items Accessibly

Like:

• Snacks

• Rain jacket

• Water filter

Constant unpacking becomes frustrating quickly.

Avoid Hanging Gear Outside the Pack

Loose gear:

• Swings around

• Throws off balance

• Gets damaged easily

Clean packing usually hikes better.

Should You Size Up “Just in Case”?

Usually not.

A better approach:

• Pack smarter

• Refine your gear over time

A slightly smaller pack often improves discipline and efficiency.

And honestly, most backpackers eventually realize they packed far too much in the beginning.

That’s normal.

Final Thoughts

Learning how to choose backpacking pack size is really about understanding your trip, your gear, and your comfort needs.

There’s no perfect universal backpack size.

But there is a backpack size that fits:

• Your trip length

• Your packing style

• Your experience level

For most beginners, staying somewhere around 50–55L is a smart place to start.

If you want to see what a well-balanced beginner-friendly 50–55L backpack looks like, you can check out Loowoko's backpack on Amazon.

Big enough for essentials.
Small enough to stay manageable.

And remember:
The best backpack isn’t the one that carries the most.

It’s the one you barely notice while hiking because it fits and carries weight properly.

That’s the real goal.

You Might Also Like:

• What Gear Do You Need for Your First Backpacking Trip?
• How to Build a Complete Backpacking Gear Kit
• Hiking vs Backpacking Gear: What’s the Real Difference?