How to Measure a Backpack for Perfect Fit

We'll begin with the suspenseful reality: most people are using the wrong backpack size! It's not a matter of guessing. Backpack sizes are determined through precise measurements. And getting it wrong? That can make or break an adventure. Here's how to avoid that.

Step 1: Know Your Torso Length
Before you even look at a backpack, you must know your torso length. This isn't your height but the distance between two critical points on your back. The torso length determines the frame size of the pack.

1. Find your C7 vertebra: This is the bony protrusion at the base of your neck. When you tilt your head forward, the most prominent bone that sticks out is the C7.
2. Locate your iliac crest: Now, put your hands on your hips. Move them up until you find the upper edge of your hip bones (these are your iliac crests). Imagine a horizontal line connecting both your iliac crests—this line is your measurement endpoint.
3. Measure the length: Using a flexible tape measure, ask someone to help you measure the distance between the C7 and the imaginary line between your iliac crests. That's your torso length.

Here's a simple chart to determine your size:

Getting the torso length right is crucial because it ensures that the pack's shoulder straps sit correctly, allowing you to carry the load efficiently.

Step 2: Hip Belt Sizing
Your hips carry most of the weight—around 80% of the load should rest on your hips, not your shoulders. This is where the hip belt comes in. To measure:

1. Measure your waist at the iliac crest: Use a soft measuring tape to wrap around your hips, where the belt will sit.
2. Adjustability: Most backpack hip belts are adjustable, but knowing your exact size ensures a snug fit. The belt should sit comfortably without being too loose or too tight.

Step 3: Backpack Volume
Volume is measured in liters and is determined by your trip's length and the gear you need to carry. Here's a quick breakdown:

• Day hikes (10-20L): Perfect for essentials like water, snacks, and a light jacket.
• Weekend trips (20-40L): Ideal for one to two nights, carrying clothing, food, and a sleeping bag.
• Multi-day trips (40-70L): For longer adventures, these packs hold everything from tents to cooking gear.
• Extended treks (70L+): These are for serious backcountry expeditions, where you'll need to carry significant amounts of food, gear, and possibly more technical equipment.

But remember, bigger isn’t always better. Carrying more volume than you need means extra weight.

Step 4: Frame Types
Backpacks come with different frame designs that affect how they distribute weight. The frame style you choose depends on your activity.

• Internal Frame: Most common for hiking and backpacking. These packs hug your body and keep the load close, offering better balance on rough terrain.
• External Frame: Best for carrying heavy loads, especially on flat ground. They keep the weight off your back, allowing airflow but are less popular today.
• Frameless: Ultra-light for minimalists, but these packs offer less support, making them less ideal for heavy loads.

Step 5: Load Adjusters and Fit Customization
High-quality backpacks come with multiple ways to adjust the fit:

• Load lifters: Straps that connect the top of the pack to the shoulder straps. Tightening them helps keep the load closer to your body.
• Sternum strap: Helps to pull the shoulder straps together, stabilizing the pack.
• Hip belt adjustments: Ensures that the load is centered on your hips.

Take time to fine-tune these adjusters to make the backpack an extension of your body rather than a burden.

Step 6: Try It On and Test It
Once you’ve selected the right size and frame type, try the backpack on—preferably loaded with weight. This will give you a real sense of how it feels under pressure.

1. Load the backpack: Add weight to simulate the load you plan to carry.
2. Put it on and tighten: Start with the hip belt, tighten the shoulder straps, and then adjust the load lifters.
3. Walk around: Test it on different terrains. Does it sway? Does it dig into your shoulders or hips? A perfect fit means you shouldn’t feel discomfort after a few minutes of walking.

Step 7: Special Features and Considerations
Some additional features that might affect the fit and comfort of your backpack include:

• Ventilation: Some backpacks feature mesh back panels that allow airflow, which is essential for hot weather trekking.
• Hydration compatibility: Many packs have built-in compartments for hydration bladders, which can help with water access during hikes.
• Rain cover: Having an integrated rain cover can protect your gear in wet conditions.
• Pockets and accessibility: External pockets for water bottles, side zips for easy access to the main compartment, and stash pockets for quick-grab items all contribute to the convenience of your pack.

Key Takeaway: Measuring your backpack involves understanding your body and the specific demands of your trip. Torso length, hip size, and pack volume are non-negotiable factors to get right. Investing the time to measure properly will save you from discomfort and ensure a more enjoyable adventure. A well-fitted backpack should feel like a natural extension of your body, allowing you to focus on the beauty of the outdoors, not on adjusting your gear every few steps.