How brands' heel-to-toe drop measurements differ from reality in running shoes

Ever laced up a fresh pair of running shoes, taken your first strides, and felt that the promised heel-to-toe drop simply doesn't match reality? If you've ever found yourself in this situation, you're not alone.

It's a scenario all too familiar for many runners and one that stems from a surprising fact: brands fail to accurately state the heel-to-toe drop of their running shoes. Sometimes, these discrepancies aren't minor—they can be as substantial as a whopping 168% deviation from the declared figure.

In this article, we will investigate the importance of understanding the correct heel-to-toe drop of running shoes and unravel the reasons behind these prevalent inaccuracies.

What is the heel-to-toe drop?

Often referred to simply as the "drop," the heel-to-toe drop is a critical feature of all running shoes. This term signifies the height difference between the heel and the forefoot in a shoe, measured in millimetres. This measurement offers insights into the positioning of your foot in the shoe during your run.

A shoe exhibiting a high drop (8-15 mm) will present a noticeable slant, with your heel significantly higher than your toes. In contrast, a shoe with a low drop (0-4 mm) will have your heel and forefoot nearly on the same level.

Grasping the concept of the heel-to-toe drop can guide you in selecting a shoe tailored to your running style and biomechanics.

For instance, a lower drop may offer advantages for midfoot or forefoot strikers who prefer a more natural stride. Conversely, a higher drop typically complements those who tend to strike with their heel. For a more thorough exploration of heel-to-toe drop, check our ultimate guide that covers everything you need to know.

Our methodology: Accuracy is our priority

You might be wondering whether the heel-to-toe drop measurements could differ based on where the calliper is applied on the heel and forefoot. However, thanks to the official guidelines from World Athletics, we can assure you that this isn't an issue at all. According to the rules:

1. The stack height must be determined at the centre of the shoe, rather than the sides.
2. The forefoot's measurement should occur at 75% of the shoe’s internal length, while the heel should be clocked at 12%.

Achieving this degree of accuracy is impossible without cutting the shoe in half—a method that's our signature approach. As a result, we can guarantee 100% precision in our measurements, because adhering to these specifications is the only way to guarantee a real heel-to-toe drop.

For those of you who pay close attention to details, you may have already noticed that each shoe we test in our lab has a vertical line drawn on the midsole in the stack height images. This marks the exact point where we take our measurements.

For this reason, a heel-to-toe drop measurement can only be deemed trustworthy if it has been precisely taken in strict accordance with these specified guidelines.

Our lab's verdict

To highlight how brands misreport drop measurements, we will disclose 10 popular models drawn from the pool of 122 running shoes we've analysed in the lab.

We'll compare the numbers reported by the brands against our measurements. Remember that ours are made following the official guidelines by WA.

Our analysis clearly shows that while some shoes have only minor discrepancies from the brand-reported numbers, others exhibit variations of up to 50%. 

These significant inconsistencies can drastically alter how a shoe performs, potentially differing from your expectations. That's why it's crucial to know the true drop of a shoe.

Measuring the magnitude of brands' deviation

We've already proven that the actual heel-to-toe drop veers significantly from the numbers brands provide. The question is, how substantial is this discrepancy? To shed light on this, we propose using an effective strategy—a percentage comparison. 

We'll evaluate the heel-to-toe drop of 115 shoes—we've omitted the most extreme outliers—showing their deviations in 10% intervals. This systematic analysis will provide a clear illustration of the extent to which brands, in general, diverge from reality.

This chart offers us two clear insights:

1. Nearly every shoe deviates somewhat from the brand's stated drop. Still, over half fall within the 0-19% range—an acceptable margin that shouldn't significantly affect your biomechanics.
2. Concerningly, more shoes cluster in the +50% group than in the 30-39% and 40-49% groups combined.

This leads us to question whether there might be significant differences between brands—or perhaps there aren't any significant differences at all. Let's find out.

Data analysis from our lab-tested shoes leads us to a definitive conclusion: no single brand offers reliability when it comes to drop numbers. 

Some, like Nike and Adidas, come closer to official specifications, while others such as New Balance and Hoka exhibit larger deviations. But as it stands, it's currently unfeasible to fully trust brand-provided data.

Largest drop discrepancies

Following our in-depth analysis of these differences, we've gathered a wealth of data. And we are sure that most of you are intrigued by the most extreme cases, so let's dive into those.

Here are the top 6 disparities we discovered in our measurements—3 showing an overstated drop and 3 an understated one:

Why it’s important to know the real drop in a running shoe

Our lab tests have consistently revealed that the official heel-to-toe drop values declared by brands don't always match the actual measurements.

To illustrate this point, let's consider a practical example. Imagine you're on the lookout for a competition shoe for your upcoming marathon, and the Nike Alphafly 2 catches your eye.

As a heel striker, you would typically favour a shoe with a higher heel-to-toe drop—the Alphafly 2 would seem to fit the bill with Nike stating it has an 8-mm drop. However, our measurements indicated a drop of only 4.7 mm. This discrepancy makes the shoe a more suitable choice for midfoot or forefoot strikers rather than heel strikers.

The crucial takeaway here is that relying solely on manufacturers' specifications might lead to a suboptimal shoe choice. Our findings highlight the need for third-party verification of these critical measurements.

For instance, this study has indicated that significant changes in heel-to-toe drop require an adaptation period. Without accurate knowledge of the actual drop of your new running shoes, you could unwittingly expose yourself to potential injuries.

Conclusion: No brand provides accurate heel-to-toe drop measurements

We really hope for a future where all brands are required to provide official stack height and drop data following World Athletics regulations, as this standardisation would ensure consistency across all brands.

Until that time—that probably will never come—you can count on us at RunRepeat to provide exact measurements on the heel-to-toe drop of running shoes.