How Is Cushioning Measured In Walking Shoes? A Guide To Stack Height & Midsole Softness

In walking shoes, cushioning is measured using two primary metrics: stack height, which determines the amount of cushioning material, and midsole softness, which measures the firmness of that material. Together, these measurements provide an objective way to understand how a shoe will absorb impact and feel underfoot.

The key to understanding shoe cushioning is recognizing that it isn't a single value. True comfort and performance come from the interplay between the total thickness of the sole (stack height) and the material's actual hardness (durometer rating).

How is cushioning measured in walking shoes? A Guide to Stack Height & Midsole Softness

The Two Core Metrics of Cushioning

To properly evaluate a walking shoe, you must look at both of the following objective measurements.

Stack Height: The "How Much"

Stack height is the total amount of material separating your foot from the ground, measured in millimeters (mm) with a precision caliper. It directly corresponds to the volume of cushioning.

A higher stack height generally means more potential for shock absorption. For prolonged use or walking on hard surfaces, a heel stack height of 30 mm or more is often recommended for superior impact protection.

Midsole Softness: The "How It Feels"

Midsole softness, or hardness, is measured using a tool called a Shore A durometer. This device presses a standardized point into the foam to determine its resistance.

This measurement, given in HA units, tells you how the cushioning will feel.

Below 20 HA: Considered very soft, providing a plush, "cloud-like" experience.
20-30 HA: A balanced feel, offering a mix of softness and responsiveness.
Above 30 HA: Considered firm, providing more stability and a better feel for the ground.

Beyond the Numbers: Cushioning Materials

While early athletic shoes used simple rubber, modern cushioning is a complex science.

Today's midsoles are made from advanced foams, sometimes supplemented with specialized technologies like air units, gel pods, or other proprietary fluid systems. These materials are engineered to be lightweight and responsive despite their thickness.

Understanding the Trade-offs

Choosing the right cushioning involves balancing competing priorities. There is no single "best" specification for everyone.

Softness vs. Stability

Extremely soft, "max-cushion" shoes are excellent for absorbing impact on hard surfaces like concrete, especially for those with neutral pronation.

However, this softness can come at the cost of stability. Some users may find that an overly soft or high-stacked shoe feels "tippy" and less secure, particularly on uneven ground.

Protection vs. Ground-Feel

A thick, high stack height is ideal for protecting your joints from repetitive impact over long distances.

Conversely, a firmer, lower-stack shoe provides a more direct connection to the ground. This can enhance stability and proprioception (your sense of body position), which some people prefer.

Making the Right Choice for Your Needs

Use these technical measurements to find a shoe that aligns with your specific goal.

If your primary focus is maximum impact absorption: Look for a shoe with a high heel stack height (30mm+) and a low durometer reading (below 20 HA).
If your primary focus is a balance of comfort and stability: Seek a shoe with a moderate stack height and a durometer reading in the balanced range (20-30 HA).
If your primary focus is stability and a responsive feel: Prioritize a shoe with a firmer durometer reading (above 30 HA), as stack height becomes less critical.

By understanding these two simple measurements, you can move beyond marketing terms and make an informed decision based on objective data.

Summary Table:

Measurement	What It Is	Key Insight
Stack Height	Total thickness of the sole (in mm)	Higher stack (30mm+) = more potential impact absorption.
Midsole Softness	Firmness of the foam (measured in HA)	Lower HA (<20) = softer feel; Higher HA (>30) = firmer, more stable feel.

Need walking shoes with the perfect cushioning for your customers?

As a large-scale manufacturer, 3515 produces a comprehensive range of footwear for distributors, brand owners, and bulk clients. Our production capabilities encompass all types of shoes and boots, allowing us to precisely engineer cushioning systems—from advanced foams to proprietary technologies—that meet specific market demands for comfort, stability, and performance.

Contact our experts today to discuss your custom footwear needs and leverage our manufacturing expertise.