How to Choose Your Backpack Size: A Beginner's Guide
How to Choose Your First Backpacking Pack
You're ready to buy your first backpack, but the size dilemma paralyzes you. Should you get a 40L, 50L, or 70L? Do you buy the pack first or after other gear? I analyzed expert advice and real-world testing to cut through the confusion. Getting this wrong means discomfort on trail or wasted money. Let's solve this step-by-step.
Understand Your Backpacking Style First
Your trip type dictates everything. A weekend warrior needs different gear than a thru-hiker covering thousands of miles. Expedition trips with specialized equipment? That's another category entirely.
I've seen hikers struggle because they mimicked someone else's setup without considering their own needs. For example:
- Ultralight 40L packs work for summer minimalists but fail in winter
- 70L expedition packs overwhelm weekend trips with unnecessary bulk
- 50-65L offers the sweet spot for most beginners
Key questions to ask yourself:
- How many nights are your typical trips?
- What seasons will you hike? (Winter gear needs 30% more space)
- Are you carrying specialized gear like packrafts or climbing equipment?
Volume vs Load Capacity: Critical Differences
New hikers often confuse these two factors. Volume (measured in liters) determines how much gear fits. Load capacity dictates how comfortably the pack carries weight.
Real examples from my field tests:
- The Outdoor Vitals 40L ultralight: Max 30 lbs comfortably
- Gregory Paragon 50L: Handles 35-40 lbs with its robust frame
- Superior Wilderness Designs 70L: Carries 45+ lbs for heavy loads
A winter trip exposes volume limits. When I tried forcing a 4-season sleep system, tent, and insulated layers into a 40L pack, critical items wouldn't fit. That same gear slid easily into a 70L with room for food.
Frame Design Determines Comfort
The best volume means nothing if the frame can't handle your weight. After testing dozens of packs, I found three key design elements:
Frame type:
- Ultralight frames (carbon stays) flex at 25+ lbs
- Traditional frames (aluminum stays) hold 35+ lbs
- Expedition frames (reinforced stays) manage 45+ lbs
Adjustability:
- Hip belts with multiple pivot points reduce pressure points
- Torso-length adjustments prevent shoulder strain
Suspension quality:
- Look for 10+ mm thick padding on belts
- Ventilated back panels reduce sweat buildup
Your Step-by-Step Selection Process
- Determine your trip profile (weekend vs thru-hike)
- Source core gear first (sleep system, shelter, cookset)
- Calculate total packed volume:
- Arrange gear in a cardboard box
- Measure box dimensions (LxWxH in inches)
- Convert to liters: (LxWxH)/61 = approximate liters
- Weigh your full kit:
- Include food and water (2L water = 4.4 lbs)
- Add 10% buffer for unexpected items
Pro tip: Rent different pack sizes before buying. Many outfitters offer affordable rental programs.
Capacity Recommendations by Scenario
| Trip Type | Recommended Size | Real-World Example |
|---|---|---|
| Summer weekends | 40-50L | 2-3 nights, fair weather |
| 4-season adventures | 60-70L | Winter trips, bulky gear |
| Thru-hiking | 50-55L | Ultralight, resupply often |
| Expedition loading | 70L+ | Technical gear, group gear |
Critical Mistake: Ignoring Your Body Type
A "perfect" 50L pack fails if it doesn't fit. I've watched hikers suffer because they bought online without sizing. Your torso length (C7 vertebra to iliac crest) determines frame size, not height.
Two non-negotiable steps:
- Measure your torso with a tape measure
- Test loaded packs with 20+ lbs for 15+ minutes
Brands with exceptional adjustability:
- Osprey (Anti-Gravity suspension)
- Gregory (Response A3 system)
- Deuter (VariQuick adjustment)
Action Plan: Buy Your Pack Confidently
- Borrow gear to estimate volume before purchasing
- Rent first if testing multiple sizes
- Prioritize fit over features - no "cool" pack is worth blisters
- Verify return policies - reputable brands offer trial periods
Beginner hack: Start with a 55L pack. It's the most versatile capacity for 3-season trips while leaving room for skill growth.
The Unspoken Truth About Pack Sizes
Your first pack won't be your last. As your skills evolve, so will your gear. That 70L brute that served your beginner phase might give way to a streamlined 48L later. This progression is normal – don't feel locked into one size forever.
Your Backpack Sizing Checklist
- Determined primary trip style
- Measured torso length accurately
- Tested packed weight of core gear
- Researched frame types for your load needs
- Verified store return policy
Which step feels most overwhelming right now? Share your biggest sizing concern below – I'll help troubleshoot common mistakes. Remember: The right pack transforms your experience. A few hours of research prevents years of discomfort.
