What is Back Length?

The breadth of packs in our range can be very confusing. Many packs come in regular, large and ND sizes and many have adjustable back systems.

This page contains information on which size pack you should buy and how best to achieve your ideal fit.

Your torso length can be found by measuring from your C7 vertebra (the bony protrusion from the back of your neck when looking down) to the height of your iliac crest (top of your hip bones, where you put your hands on your hips).

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

Our AdaptiveFit harness means 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 20inches. We also have adjustable back systems and alternative back lengths on many styles of packs in our ranges.

As a guide our packs fit as follows:

Fixed Back Systems

ND (Small / Womens) Regular Large
16"/ 41cm 18"/ 46cm 20" / 51cm


Adjustable Back Systems

Range ND(Small / Womens) Regular Large
Axiom 3/5/7 15-20" / 38-51cm 17"-22" / 43cm-56cm 19"-24" / 48-61cm
AirZone Centro 16"-18" / 41-46cm 18"-20" / 46-52cm N/A
Cholatse 16"-18" / 41-46cm 18"-20" / 46-52cm 20"-22" / 52-56cm
Eclipse 16"-18" / 41-46cm 18"-20" / 46-52cm 20"-22" / 52-56cm


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