In order to properly select a backpack that fits. You need to get two measurements. The first measurement is at your hip line.
Get a flexible tape measure and measure your circumference at the top of the hips. This will be your measurement for your hip belt. Most companies use the following chart. However, you may want to double check the sizing guide on the companies website just to be sure.
- Small – 22 to 27 inchs (56-69 CM)
- Medium – 28 to 34 inchs (70-87 CM)
- Large – 35 to 39 inchs (88-100 CM)
- X-Large – 40 to 45 inchs (101-114 CM)
The next measurement you need is the length of your torso. You get this by measuring the distance from your 7th vertabrae to the spot in your spine equal to your iliac crest.
Find your hip bones in the front of your body. Once you locate your hip bones, move your fingers to the same spot in your back. Leave a finger in that spot. Now tilt your head forward. Use your other hand to find the first big bone that sticks out at the base of your neck and top of your back. This is your 7th Vertebrae. Now measure the distance between your two fingers. This is your torso length.
- X-Small – up to 15 ½ inches (up to 39 CM)
- Small – 16 to 17 ½ inches (40 to 45 CM)
- Medium – 18 to 19 ½ inches (46 to 50 CM)
- Large – 20 and up (51 CM and up)
Some companies make gender-specific backpacks and their measurements may vary. Check the company website before committing to buy a gender-specific pack.