Backpack size guide

Whether you’re trekking the Himalayas, sport climbing or fell walking, you need a backpack that moves with you across the terrain. Finding your back length measurements will help you to select the right size pack for your body for the most comfortable carry, wherever your adventures take you. 


What is back length?

Your back length can be found by measuring from your C7 vertebra (the bony protrusion at the back of your neck) to your iliac crest (the top of your hips).

How to measure your back length to fit your backpack

You will need: 

  • A tape measure 
  • A friend to help you out 

Place your hands on your hips and tilt your head forwards. 

Ask your helper to measure from the bony protrusion at the back of your neck to where your hands sit on your hips.  

This measurement will give you an idea of which back length to choose. 


Lowe Alpine backpack size guide

As a guide our packs fit as follows:


Fixed Back:

Medium-Large  Large-Extra Large 
16″/ 41cm  18″/ 46cm  20″ / 51cm 


Adjustable Back

Lowe Alpine packs flex to fit to your body shape, so don’t worry if your back length does not measure exactly 16, 18 or 20 inches. We have adjustable back lengths on many styles of packs in our ranges.

Carry System  Small-Medium
Medium-Large  Large-Extra Large 
VT Flex / VT Plus  17-21” / 43-53cm 19-23” / 48-58cm 21-25” / 53-63cm
V-Trax  14-18” / 36-46cm 16-20” / 41-51cm 18-22” / 46-56cm
Air Contour+  17-19” / 43-48cm 19-21” / 48-53cm 21-23” / 53-58cm
Air Contour  14-18” / 36-46cm 16-20” / 41-51cm  18-22” / 46-56cm
AirZone+  17-19″ / 43-48cm 19-21″ / 48-53cm  
Kulu Airmesh  16-18” / 41-46cm 18-20” / 46-51cm 20-22” / 51-56cm