When Should You Choose a 100L Backpack for Hiking?
Wondering when you need a 100L hiking backpack? Learn how trip length, gear volume, weather, food, water and packing style determine whether 100L is right for you.
Quick Decision: Do You Need 100L?
Consider 100L if:
- Extended hiking trip
- Bulky camping equipment
- Cold conditions
- Several days of food
- Limited resupply
- Carrying equipment for others
You may not need 100L if:
- Mostly day hikes
- Short trips
- Lightweight, compact equipment
- Frequent resupply
- You already fit into 60–80L
“Do I Need 100L?” Interactive Calculator
1. How long is your typical hiking trip?
2. How bulky is your camping gear?
3. Will you hike in cold weather?
4. How often can you resupply?
5. Are you carrying shared equipment?
A buyer sees 60L, 70L, 80L, 90L, 100L and asks: “If 100L gives me the most space, shouldn’t I just buy that?”
Not necessarily. A larger backpack can provide valuable extra volume, but unnecessary capacity can encourage unnecessary packing and may result in a larger, heavier setup.
What Does 100L Actually Mean?
100L = approximately 100 liters of internal/external usable volume, depending on how the manufacturer measures capacity. 100L does not mean you should carry 100L worth of heavy equipment.
- Capacity: How much volume the backpack can hold
- Load: How much weight you’re carrying
- Fit: How well the backpack transfers that load onto your body
Key Insight:
100L is capacity, not a recommended packing target.
100L Capacity Visualized
100L is capacity, not a recommended packing target.
The #1 Reason to Choose 100L — Extended Trips
Trip duration increases the amount of food, clothing, fuel, hygiene supplies, spare equipment, and safety equipment. The longer the trip, the more important volume becomes.
When 100L Makes Sense for Multi-Day Hiking
3-day hike
- Usually don’t jump directly to 100L; compact setup may fit into a smaller pack
5–7 days
- Capacity becomes more important, especially with bulky camping equipment
1–2 weeks
- Larger pack can become useful, especially with limited resupply
Expedition-style
- 100L may become considerably more practical
Your Gear Matters More Than Your Calendar
Two hikers can take the same 7-day trip with different needs:
Hiker A
- Lightweight tent
- Compact sleeping bag
- Small stove
- Lightweight clothing
- Dehydrated food
Hiker B
- Large tent
- Bulky sleeping bag
- Heavy cooking equipment
- Extra clothing
- Larger comfort items
Don’t buy based only on the number of days. Build your gear list first.
When Cold Weather Makes 100L More Attractive
Cold-weather equipment can occupy substantially more space: insulated sleeping bags, extra layers, puffy jackets, gloves, warm hats, larger shelter systems, additional food, weather protection.
Summer vs Winter Pack
Lightweight clothing
Compact sleeping system
Small shelter
Larger sleeping bag
Insulated clothing
Extra layers
Winter accessories
SAME TRIP LENGTH — DIFFERENT VOLUME
When Limited Resupply Makes 100L Useful
If you can purchase food and supplies frequently, you don’t necessarily need massive capacity. But with limited resupply, you may need space for more food, more fuel, extra layers, backup supplies, and essential equipment.
When You’re Carrying Gear for Other People
- Parent: Children’s equipment, shared cooking, group shelter, first-aid
- Group leader: Shared equipment
- Photographer: Camera equipment
Key Insight:
Your personal hiking duration isn’t always equal to the amount of equipment you’re carrying.
100L vs 70L — Which One Should You Choose?
100L vs 80L
Choose 80L when:
- Gear is relatively compact
- You pack efficiently
- Resupply is available
- You don’t carry group equipment
Consider 100L when:
- Gear is bulky
- Weather requires more clothing
- Resupply is limited
- You’re carrying additional equipment
100L vs 90L
Do you really need the extra 10L?
90L may be enough if: Your gear already fits
100L makes more sense if: You’re consistently fighting for space
Signs Your Current Backpack Is Too Small
- You constantly attach essential equipment externally
- You have to compress essential gear excessively
- You cannot fit required clothing
- Food occupies most of your available volume
- Your sleeping system barely fits
- You regularly leave essential equipment behind
Signs a 100L Backpack Is Too Large
- You regularly hike for one day
- Your 50–60L pack has unused space
- Your gear is extremely compact
- You frequently carry an almost-empty pack
- You tend to add unnecessary items because space is available
Right Size vs Too Small vs Too Large
THE GOAL ISN’T MAXIMUM CAPACITY — IT’S APPROPRIATE CAPACITY
Don’t Forget Backpack Fit
A 100L backpack can hold a lot of gear, but if the suspension system doesn’t fit your body, the extra capacity won’t make your hike more comfortable.
- Torso length
- Shoulder straps
- Hip belt
- Sternum strap
- Load lifters
- Adjustment system
Pro Tip:
Fit is based on torso length — not overall height. Two people of the same height can need different backpack sizes. See our complete guide to choosing a large adventure backpack.
Weight Is Different From Capacity
They are not the same thing. A large backpack doesn’t automatically mean you should carry more weight.
How to Pack a 100L Backpack Without Filling Every Liter
- Lay all essential equipment on the floor
- Remove duplicates
- Group equipment by category
- Measure bulky items
- Pack the essentials first
- Only then consider optional comfort items
- Leave some organizational flexibility
Should Beginners Buy a 100L Backpack?
Yes, if:
- Specifically preparing for extended, gear-heavy adventures
No, if:
- Mainly doing short hikes and want a general-purpose pack
Is 100L Good for Camping and Travel?
A 100L backpack can be useful for extended camping, adventure travel, long-distance hiking, remote outdoor trips, and gear-heavy expeditions.
Common Mistakes When Choosing 100L
Before You Buy 100L — Interactive Checklist
Useful Resources
REI Backpack Guide REI Fit Guide REI Packing Guide NPS Hike Smart US Forest Service American Hiking Society Leave No Trace TSA TravelFrequently Asked Questions
Is a 100L backpack too big for hiking?
Not necessarily. It can be appropriate for extended trips, bulky equipment, cold-weather gear or situations where resupply is limited. For short trips, however, it may be unnecessary. See is it too big? for more.
How many days is a 100L backpack good for?
There is no universal number. Trip duration is only one factor; gear size, weather, food requirements and resupply opportunities also matter.
Do I need a 100L backpack for a week-long hike?
Not automatically. Many hikers can complete a week-long trip with less capacity if their equipment is compact and they can resupply.
Is 100L better than 80L?
Only when you need the additional volume. Compare sizes before deciding.
Is 100L too big for a beginner?
It depends on the beginner’s intended trips. For short recreational hikes, probably. For extended gear-heavy adventures, it may be appropriate.
What is the biggest advantage of a 100L backpack?
Additional usable space for bulky or numerous items.
What is the biggest disadvantage?
The extra capacity can encourage overpacking and may come with additional bulk and weight.
Can I use a 100L backpack for camping?
Yes. Camping equipment can be bulky, making larger backpacks useful for some camping trips. See camping guide.
Should I choose 90L or 100L?
Choose based on your actual gear. If everything fits comfortably in 90L, you may not benefit much from the extra 10L. Read our comparison guide.
What should I consider besides capacity?
Fit, suspension, hip belt, frame, weight, materials, organization, durability and weather protection. See our how to choose guide.
Final Decision Matrix
Don’t Ask “What’s the Biggest Backpack?” Ask “How Much Space Does My Actual Adventure Require?”
Ready to evaluate a 100L backpack?
Start with your gear list, then explore the AdventureSupplier 100L.
Explore the 100L Adventure Backpack
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