Choosing a backpack starts with matching its volume to your trip length and its suspension to your torso measurement, not your height.
Most people pick a pack by height or brand loyalty and end up carrying the load on their shoulders. The real process takes two measurements and one hard look at what you’ll carry.
Start With Pack Volume
Pack volume is measured in liters—the most important spec after fit. Too small, and gear gets strapped outside; too large, and the pack weighs more empty than it should. Weekend trips need 40–55 liters; week-long trips need 55–70 liters; expeditions and winter trips push into 70–90 liters. Day hikes need only 10–30 liters; short errands or hydration-only carries need 0–10 liters.
Measure Your Torso, Not Your Height
Backpacks fit torso length, which has almost nothing to do with overall height. Two people both 5’10” can need different sizes. Have a friend find the C7 vertebra (prominent bump at the base of your neck), then the top of your hip bones (iliac crest) and bony point at the base of the lumbar spine. Measure the distance in inches—that number determines your pack size range. Hip circumference also matters: the belt must sit just above the hip bones.
Check Fit On The Store Floor
Once you’ve found a pack in the right size, load it with 15–20 pounds of gear or store bags and walk for ten minutes. Check for gaping between shoulder strap and shoulder (pack too big) or straps pressing into your neck (pack too small). The sternum strap keeps shoulder straps off your collar bones. With the hip belt cinched just above your hip bones, shoulder straps should rest lightly without bearing the load. If weight pulls down on your shoulders, the hip belt is too low or suspension is wrong. Adjust load lifters, shoulder straps, and hip belt straps until the weight settles on your hips.
What About Durability And Features?
A bottom sleeping bag compartment keeps heavy gear low and centered. Internal hydration sleeves are standard on serious packs. If you carry trekking poles or an ice axe, confirm attachment loops exist. A rain cover is practical for wet conditions.
The Practical Middle Road
For general-use backpacking packs that work for most people: 50–60 liters, 4-pound empty weight, a frame that fits your measured torso. Brands like Osprey, The North Face, and Patagonia make models in this range. The Osprey Exos 58 is a frequently recommended starting point, but every brand fits differently. For everyday or school use, factors shift toward organization and style. Readers looking for daily commuting should check our roundup of the best business backpack for women, where pocket layout, laptop protection, and professional appearance are priorities.
| Trip Type | Pack Volume Range | Typical Load |
|---|---|---|
| Day hike / hydration | 10–30 L | 5–15 lbs |
| Weekend backpacking | 40–55 L | 15–30 lbs |
| Week-long backpacking | 55–70 L | 30–50 lbs |
| Expedition / winter | 70–90 L | 50–70+ lbs |
| Middle-road general use | 50–60 L | 20–40 lbs |
FAQs
Can I use a school backpack for weekend hiking?
School backpacks lack a proper frame and hip belt, so weight sits on your shoulders. For any load over 10–15 pounds, this becomes painful within a few miles.
Should I buy a bigger pack than I need for future trips?
No. A larger pack is heavier, harder to balance, and encourages overpacking. Choose volume for 80% of your trips; rent a larger one for rare expeditions.
How do I know if a pack fits without trying it on with weight?
You can’t. Unloaded packs feel comfortable on the store floor and become uncomfortable with 20 pounds inside. Always test with weight. Most outdoor retailers let you load a floor model with sandbags or weighted gear.
References & Sources
- REI. “How to Choose a Backpack — Expert Advice.” Guide covering volume, fit, torso measurement, and suspension setup.
- The New York Times Wirecutter. “The Best School Backpack for High School and College.” Recommendations and testing criteria for everyday use.
- Appalachian Mountain Club. “How to Choose the Right Backpacking Pack for Your Next Adventure.” Covers load distribution, fit testing, and sizing for backpacking trips.