Outdoor Backpack Sizing and Fit Guide

Pack Smart. Hike Far.

Heading into nature is about more than enthusiasm — it’s about preparation. Having the right outdoor backpack is essential to ensure your journey is comfortable and successful.

Whether you’re out for a few hours or several days, choosing the correct backpack can make all the difference. This guide will help you understand the options available and how to find the one that suits your adventures best.

What You'll Learn

• Get a clear understanding of backpack sizes and what they’re meant to carry.

• Learn the differences between various backpack styles and their best uses.

• Find out how to select a pack based on its size, comfort level, adjustability, and features.

• Discover how to take your body measurements to ensure a proper fit.

• Master the steps to correctly wear and adjust your hiking backpack.

Backpack Types by Trip Duration

Backpack Type	Best Use Cases	Capacity Range	Trip Length
Day Backpack	Short hikes, travel, daily outings	30–35 liters	1 day
Weekend Backpack	Overnight camping, short hiking trips	30–50 liters	1–2 nights
Multi-Day Backpack	Longer backpacking, remote hunting or camping	50–80 liters	3–5 nights
Week-Long Backpack	Extended expeditions, winter adventures	70+ liters	5+ nights

How to Measure for Fit

Finding the right fit starts with measuring your torso and hip size.

Measuring Torso Length

1. Locate your C7 vertebra — the prominent bump when your head tilts forward.

2. Rest your hands on your iliac crest (the top edge of your hip bones).

3. Measure the straight line between these two points down your back.

Measuring Hip Circumference

Wrap a tape measure around your hip bones, not your waist. This is where the hip belt will sit and carry the load.

Step-by-Step Backpack Fitting Guide

For accurate fitting, load your pack with 10–20 lbs to simulate real use.

Step 1: Adjust Torso Length

Set the suspension system to match your torso measurement.

Step 2: Secure the Hip Belt

Fasten the belt snugly around your hip bones — this distributes the bulk of the weight.

Step 3: Adjust Shoulder Straps

Pull the straps so they contour your shoulders without bearing too much weight.

Step 4: Tighten Load Lifters

Gently tighten these small straps above your shoulders to stabilize the pack’s top.

Step 5: Position the Sternum Strap

Place it slightly below your collarbone and secure it for improved control.

 

Backpack Frame Options

Frame Type	Description	Ideal Use
Internal Frame	Internal stays keep pack close to body for better balance	Technical terrain, climbing, off-trail hiking
External Frame	Visible metal frame, great for gear-heavy setups	Long trails, carrying bulky equipment
Frameless	Lightweight design without structure	Minimalist hikers, ultralight treks
Hybrid Frame	Mix of support and flexibility with removable parts	All-around versatility

Smart Backpack Features to Look For

• Built-in hydration sleeve for easy access to water

• Detachable daypack for basecamp flexibility

• Sleeping bag compartment keeps gear organized

• Attachment loops for tools and trekking poles

• Ventilated mesh back panel reduces sweat buildup

• Belt pockets for items like snacks or a compass

• Extra cushioning on straps and waist for long wear

Next Stop: Adventure

Choosing the right backpack means thinking about your needs: duration, terrain, gear weight, and body type. Once you know those — finding a well-fitted pack is easy.

Browse our full collection at Terraincognita Backpacks and gear up for your next trail experience.

The right pack makes every step more enjoyable!