With footwear being one (and especially important) component of a successful and enjoyable hike, it can pay to become a bit more familiar with the terminology used to define and classify all the choices that are out there. When it comes to stack height, this is a specific measurement of the distance of the bottom of your foot from the ground and overall height of the shoe underfoot. Generally when comparing footwear in a similar class, most of the differences in stack height will be in the form of midsole (the cushioning layer between the outsole and insole) height variance.

For stack height a balance must be struck. Too thick and stability, along with one’s ability to feel the ground is significantly hindered. Too thin and cushioning is compromised, along with the ability of the shoe to protect the foot from rocks or other sharp objects. For a hiking boot or shoe, a rockplate or plastic layer will often be integrated into the midsole for additional protection in this regard. Stack height is expressed in millimeters and the best way to determine your own favorite stack height is by trial and error.

Considering Stack Height

The right choice of shoes is critical to successful and enjoyable hiking, and as such it can help to pay attention to the stack height specification of your existing footwear and when selecting something new. When shopping for new footwear, look up the stack height of your current shoe and using past experience with that particular stack height as a guide, one can begin to narrow down footwear choices and eventually find your own ideal stack height range. This will vary from person to person, by gait, and technique / foot placement on rocky ground, and often will go up with pack weight. To lessen the risk of injury and any discomfort, I like to accompany any large change in stack height with an adjustment period and a slow ramp up of mileage to let my feet and body adjust over time.

The Best Shoe Stack Height for Backpacking & Hiking

The best stack height is without a doubt a personal choice, but once you've found your sweet spot you can continue to seek out new and replacement footwear with stack heights equivalent to what you know works. You may also see different stack heights listed for both the heel and forefoot of a shoe. This can be used to determine the "drop" of the shoe, or the differential between the heel and forefoot heights.

The same stack height between the heel and forefoot results in a "zero-drop" shoe. Over the years, I've come to prefer a stack height around 25mm as can be found in the Altra Lone Peak series of trail running shoes. However, if we were to stay in the Altra line, many hikers prefer the higher stack height of the Olympus shoe (usually, higher stack height means more cushioning but less stability) especially when hiking on more graded trails. For more on hiking footwear, see our guide on how to choose the best hiking shoes or boots.

Editor's Note: This Jargon installment originally appeared in Issue 46 of TrailGroove Magazine. You can read the original article here.