Ultralight Packs

Consider your main activity:

• Hiking: Compatible with hydration reservoirs; some have straps or loops to attach trekking poles or other gear.
• Running: Designed to limit bounce; compatible with water bottles or hydration reservoirs.
• Climbing: Slim profile with abrasion-resistant reinforcements.
• Traveling: Has compartments for easy organization; many meet carry-on size requirements.

How much gear will you carry?

• 20L or less: Ideal for short runs, day hikes or quick outings.
• 21–35L: The sweet spot for hiking and travel.
• 36–50L: Best for extended trips or adventures requiring more gear or clothing.

Find the right fit:

• Daypacks are available in a range of sizes.

• Check your torso length and waist against the brand's size chart for the best fit.
• Many packs feature adjustable torso lengths to fine-tune your fit.

Choose a gear capacity 

• Runs under 2 hours: 2 liters 
• Runs 2-3 hours: 2 to 6 liters 
• Runs 3-6 hours: 4 to 12 liters 
• Runs over 6 hours: 6+ liters 

Decide on bottles and/or reservoir 

• Most vests are compatible with both bottles and reservoirs. 
• Bottles are easier and faster to refill, usually holding 500 ml of water each. 
• Bottles can be soft or rigid. Rigid bottles are more durable.  
• Reservoirs hold more water, up to several liters. 

Get the right fit 

• Follow the manufacturer’s sizing guidelines. 
• Choose a snug fit. (Measure your chest while wearing your sports bra.) 
• Leave room for adjustment: The straps should sit in the middle of their adjustment range. 
• Women-specific vests offer fits optimized for the bust and shoulders. 

Choose a bag category

• Wheeled luggage: Easy to roll through airports and on smooth streets; options include duffels, suitcases and backpacks with wheels
• Travel duffel bags: Lighter, simple design and easy to stash, but with limited organizing compartments
• Travel packs: Ideal for uneven terrain and travelers OK carrying a load on their backs

Capacity

• Weekend trips (30-50 liters): Many carry-on duffels, packs and bags fall in this range
• Multiday trips (50-75 liters): Great for trips that last one to two weeks
• Extended trips (75+ liters): Best for big expeditions or longer adventures

Features

• Carry-on: These meet common carry-on guidelines, but always check airline rules before heading out
• Laptop compartment: A dedicated sleeve or section helps protect your device   
• Backpack straps: Some duffels also have dedicated backpack straps for easy hauling

Backpack capacity

Backpacking packs can be 30 to 70-plus liters. To choose the right capacity, consider trip duration and the gear you’ll bring.

Backpack features
Think about the frame type, location of important pockets, padding and ventilation, among other things.

Backpack fit
Your pack should be sized for your torso length (not overall height) and hip circumference. You can try on packs at your local REI store.