How to Measure Your Back Length for a Backpack

Getting the right back length is one of the most important steps in choosing a backpack that fits well and carries comfortably. Unlike clothing sizes, backpacks are fitted to your torso length, not your overall height. Two people of the same height can have very different back measurements.

A correctly sized pack transfers weight efficiently onto your hips, improves stability, and remains comfortable over long days on the trail.

What You'll Need

• A flexible tape measure

• A friend to help (recommended)

  
  

Step 1: Find Your C7 Vertebra

Tilt your head forward slightly and locate the prominent bone at the base of your neck. This is known as the C7 vertebra and forms the upper point of your measurement.

Step 2: Locate Your Iliac Crest

Place your hands on your hips with your thumbs pointing towards your spine. The line joining the tops of your hip bones (the iliac crest) marks the lower point of the measurement.

Step 3: Measure Your Torso Length

Stand naturally and measure from the C7 vertebra down the centre of your spine to the point where the line between your hip bones meets your back.

This measurement is your back length.

Southern Lite Sizing Guide

Size	Back Length
Small	39–43 cm
Medium	44–49 cm
Large	50–55 cm

If your measurement falls between sizes, get in touch and we'll help determine the best fit based on how you intend to use the pack.

Measuring for a Hip Belt

A properly fitted hip belt is essential, as it transfers most of the pack weight onto your hips rather than your shoulders.

To determine your hip belt size, measure the circumference of your hips at the point where you would normally wear the backpack's hip belt. This is typically around the top of your hip bones (iliac crest) rather than around your waist where you would wear trousers.

Stand naturally and wrap the tape measure around your body, keeping it level all the way around. The tape should be snug against your clothing but not pulled tight.

Hip Belt Sizing Guide

Hip Measurement	Hip Belt Size
70–80 cm	Small
80–90 cm	Medium
90–100 cm	Large

If your measurement falls between sizes, or if you regularly wear bulky winter clothing, please get in touch and we'll help determine the best option for your intended use.

All Southern Lite hip belts are fully removable and interchangeable. If your size changes over time, or you need a different fit for seasonal clothing, the hip belt can be swapped out without replacing the entire pack.

Tips for Accurate Measurements

• Stand in a relaxed, natural posture.

• Have someone else take the measurements whenever possible.

• Measure twice to confirm the result.

• If you're between sizes or unsure, get in touch and we'll be happy to help.

  
  

Every Southern Lite pack is designed to carry efficiently and comfortably in demanding conditions. Taking a few minutes to measure correctly ensures your pack performs exactly as intended when it matters most.