How Should Running Shoes Fit? Running Shoe Fitting Guide

It may sound silly, but it is quite important that your running shoes fit your feet properly. When trying on shoes, we tend to think of the way that a shoe fits only in terms of the length of the shoe.

However, proper running shoe fit also involves considering the width of the shoe.

In this running shoe fit guide, we will discuss how to size running shoes, the criteria to consider with running shoe fitting, and ultimately answer your questions, “how tight should running shoes should be, and how should running shoes fit?”

We will cover: 

  • How to Size Running Shoes
  • How Should Running Shoes Fit?

Let’s dive in! 

A person walking in running shoes.

How to Size Running Shoes

Many runners think that they know their shoe size, particularly in terms of length, but the size and shape of our feet change over time. In fact, a review in the Journal of Foot and Ankle Research found that up to 72% of individuals are actually wearing shoes that do not fit their feet properly. 

Pregnancy, changes in weight, aging, and even tons of running itself can potentially widen and lengthen your feet over time. 

Accordingly, it is best to measure your feet at least once a year, if not every six months. If you have experienced significant changes in weight or have gone through a pregnancy, you should definitely measure your feet afterward before buying your next pair of running shoes.

The actual size of the running shoe that you need should be determined after properly measuring your foot. 

Shelves of running shoes.

You can measure your foot at home by yourself and then compare your measurements to the shoe size chart of the brand you are interested in buying, or go to your local specialty running shop or athletic footwear store and get measured by a professional.

One important thing to note is that you need to trace and measure both feet. Many people have one foot that is longer and/or wider than the other. When buying running shoes, you need to go with the sizing that corresponds to your larger foot. 

If you have exceedingly differently-sized feet, you may want to consider buying two pairs of shoes and then using the smaller shoe on the smaller foot and the larger shoe on the larger foot. 

Of course, this will be much more costly, but it is pretty rare that your feet will be so significantly different in size to warrant this solution. 

Using different shoe lacing techniques, you can usually make the smaller foot secure and snug in a slightly larger shoe that is necessary to accommodate your larger foot.

A person getting their feet measured.

Another good piece of advice is that if you have doubts about the size you should go with after you have done your measurements, particularly if you fall between two sizes in terms of length or width, you should go with a half size up or the larger of the two sizes.

Another important thing to note is that it is best to measure your feet or go to the running store to get sized for your shoes in the afternoon or evening, particularly if you tend to run later in the day. 

Our feet swell over the course of the day, so if you measure or get fitted in the morning and you are an evening running, your running shoes may feel too snug

It is also important to measure your feet wearing the socks that you intend to run in. Some runners like wearing thicker socks with more cushioning and warmth. This can add an appreciable width and length to your feet. 

Your running shoes will feel tight if you have traced and measured your foot without socks and then choose to wear cushioned running socks. 

A person kneeling down tying their running shoe.

The same holds true for when you go get measured or try running shoes at the running shoe store. Always wear or bring the running socks that you typically train in. This will help ensure that you find shoes that will actually fit right once you have your socks on.

How Should Running Shoes Fit? 

Before we go into the specifics of what to look for and how running shoes should fit, it’s important to note that the ultimate answer is that running shoes should fit comfortably. What this means is that when you try on a pair of running shoes, the shoes should feel comfortable right out of the box. 

Some runners assume that there should be a big “break-in period,“ in which the shoes will start to stretch out or feel more comfortable. 

While it is true that the shoes may begin to soften and feel a bit more comfortable after you’ve logged a decent number of miles, the shoes should definitely feel comfortable right out of the box. If they feel too snug or stiff, it is not the right shoe or fit for you.

You can usually tell right away if a running shoe fits properly because your foot should feel comfortable and supported without being squeezed, yet the shoe should not be loose enough that you are swimming around in it.

With that said, here are some pointers for determining if your running shoes fit properly:

A pair of pink and maroon running shoes on the grass.


The upper of the shoe should fit your foot well. You should not see bony parts of your anatomy stretching or feeling like it is abutting against the inside mesh of the shoe.

Toe Box

There are two things to pay attention to with the fit of the running shoe in the toe box area. You should be able to wiggle your toes and feel like they can spread out flat without being compressed by the width of the shoe.

In terms of the length, you should have about a thumbnail’s width or half an inch between the length of your longest toe and the end of the shoe.

If your toes feel cramped either in terms of length or width, you should size up.

A person tying their running shoe.


The midfoot of the shoe should be pretty snug so that you have decent arch support, but your foot should not feel compressed from side to side.

You can adjust the tension in the shoe laces along the midfoot to get a proper fit so that it does not feel like the shoe is pulling on your foot as you run because the shoe is too tight or allowing your foot to slip up and down because the shoe is too loose.

Another important consideration with the set of the midfoot portion of the shoe is that your old anatomical mediolateral arch should line up with the arch of the shoe. 

If the arch support in the shoe is not lined up with your own arch, it can cause pain and may alter the biomechanics of your foot during the transition from your contact to toe-off.


Look at the overall shape of the shoe. The shoe last refers to the foundation that the shoe is built upon, and each running shoe brand has a different shape shoe last.

Considering the shape of the shoe extends beyond just the overall width of the shoe, some running shoes have a more squared-off forefoot region by the toes, whereas others taper more.

A person holding up the insole to the bottom of their foot.

Look at your own foot shape or tracing of your foot compared to the shape or tracing of the outsole of a running shoe, or, if possible, pull out the insole and compare it to your tracing or foot shape.

The insole shape will give you a much better idea of the actual shape and fit of the shoe. Many running shoes now build up the base of the running shoe, and they have a much wider platform than the actual shoe, particularly around the heel. 

This can skew the comparison of your own foot shape to the true shape of the inside of the shoe, which is ultimately what will affect how the shoe fits your foot.

You want the shape of the sole of the shoe to match your own shape as closely as possible.

If you have a fairly rectangular shaped foot with a broader or wider toe box area, you want this to be reflected in the shape of the shoe. On the other hand, if your foot narrows out and tapers in your toe region, look for a running shoe shape that matches this pattern.

A person tying their running shoes on a track.

Ankle Collar

The ankle collar or heel cup around your foot should be nice and snug without squeezing your Achilles tendon. 

You want there to be ample room to feel comfortable, but excessive width in the heel of the shoe will cause your heel to slip up and down as you run. This can cause blisters and irritation by constantly rubbing the back of your Achilles tendon.

If possible, test out several different brands, styles, models, and sizes of running shoes to make sure that you find running shoes that best fit your own personal foot shape and feel comfortable when you run.

Now that we have answered your questions, “how tight should running shoes should be, and how should running shoes fit?” you are ready to start looking for your perfect pair!

If you are interested in doing some initial research and comparing different running shoe brands, check out our long list of running shoe comparisons.

A person trying on a pair of shoes with a sales associate.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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