How Running Shoes Should Fit (3 Steps To Finding Your Shoe Size)

Before I went on and bought my new pair of running shoes, I wanted to make sure I get the most out of my running shoe so I Googled “How running shoes should fit”.

While doing my research, I found the best indications of properly fitted running shoes across multiple websites and decided to compile them to give you everything you need to know about choosing the right fit in one article.

If you’re in a rush for a quick answer, here’s the summary of what I found.

Running shoes should offer a snug fit around the heel and the midfoot. In addition, it should have at least a half thumb to a full thumb’s width allowance from your longest toe to the top of the shoe.

Why Finding The Right Running Shoe Fit is Important

Running is a very repetitive sport. You’ll be doin the same thing over and over again for hours on end.

Wearing a running shoe with the right fit will maximize comfort and improve your running performance. Not to mention, it will prevent premature damage to the shoe and increase its lifespan.

It also prevents blisters, hotspots, heel lifts and dead toenails.

3 Steps to Finding The Perfect Shoe Size

Step 1: Measure your foot length

For this step, you will need a pen, a paper and a ruler or measuring tape. Doing this with a friend will make the process much faster.

Stand on a piece of paper and have someone draw a line outlining your foot. Keep in mind that your feet will be larger in the afternoon when the blood starts pooling on your feet after a long day. So make sure you do this at the end of your day. Also, one foot will be larger than the other, so make sure you measure both feet.

If you’re doing this alone, place your heel against the wall and use the edge of the paper as the line for your heel

Wearing the socks you intend to wear during your runs will also help add to the accuracy of your measurement.

Once you have the outline, measure the length of your larger foot from the heel to the largest toe in centimeters.

My feet measures 26 cm. I will add 1.5 cm allowance, therefore I will find the conversion for a 27.5cm shoe.

Once you get the length of your foot, add 1 to 1.5 centimeters or about the width of half your thumb. The reason for the 1.5 cm allowance is to account for the swelling of your foot that normally occurs with running.

Step 2: Use the conversion chart

Once you have the value of the length of your feet plus 1.5cm for the allowance, it’s time to check out the sizing conversion chart of the the running shoe model you’re interested in.

In the example above, my foot length is 26cm and I will add 1.5cm for allowance. Therefore, I will find the conversion of 27.5 cm from the conversion chart.

6.525 1/4
This is a Brooks conversion chart

According to the Brooks conversion chart, my 27.5 foot length is equivalent to a 9.5 shoe.

Remember, running shoes fit differently. In the same sense, brands have different sizing from one another. So this step is important to get the right shoe size.

Your running shoe size from Nike may be different from Brooks.

Step 3: Try it on

If you’re buying from a local running shoe store, then you can test it out before you go.

However, this process may take a little longer if your buying online. You can still test it out though. Most, if not all, online stores have a return policy for picking up the wrong size.

Just make sure you don’t damage them or use them for a run or you may risk rejection for your return request.

Essentially, you’re looking for a snug fit around the heel and your midfoot with a half to full thumb’s width allowance from your longest toe to the top of the shoe. The heel must have very little movement but never slip. Lastly, your foot must not move around the shoe when you’re walking and running.

This is according to Podiatry Management’s CME Instructional program titled “Selecting the Proper Athletic Shoe”.

In other words, you must feel comfortable moving around with that shoe.

By the way, I bought a pair of Brooks Adrenaline GTS online and used this 3-step process, boy they feel snug and comfortable. I’m pretty sure I nailed my size the first time.

I highly recommend the Brooks Adrenaline GTS 21. You can buy them from Amazon.

If you need visual guidance, check out this video made by ASICS.

Courtesy to ASICS

Note that though they showed you how to use the comparison chart for ASICS, it applies to any brand.

How To Know If You Found The Right Fit

I’m surprised by the number of people who’d settle for a slightly bigger or smaller-sized running shoe. Sometimes they do it because their size is out of stock, and some do it thinking that running shoes will still expand over time.

Friends, if you still need to break into a shoe before it will start feeling comfortable, that’s a strong indication that it is the wrong size.

Running shoes must be comfortable out of the box.

There are a few things that would you that you found the right fit.

You must have at least a half thumb’s width allowance in length – We’ve talked about this earlier. This is to accommodate the swelling of the foot while running. It also prevents your toenails from making contact with the shoe that could cause dead toenails.

They should feel snug on the heel and the midfoot – Running shoes should never fit too tight nor too loose. It has to feel snug to maximize comfort and performance.

There should have very little movement on the heel – You can test this out by holding down the shoe while trying to lift your foot off the ground. In some cases, you will feel the heel lifts just by walking around. In that case, find a better fit.

Your feet should not be moving or sliding inside the shoe – Even a small movement of your foot inside the shoe will provide very discomforting friction when running. It can lead to blisters, hotspots, and dead toenails if you continue running with a loose shoe.

The eyelets should be parallel – The eyelets of the shoe should not be too far apart nor too close. A wide eyelet indicates that the running shoe is not wide enough for your foot, while a narrow eyelet indicates that your foot is too narrow for the shoe.

Also, take note that different types of running shoes may feel different. For example, a racing shoe will not feel as comfortable as daily trainers. So take that into account when choosing your running shoes.

5 Benefits of a Proper Fitting Shoe

  • Increases overall running performance
  • Maximizes comfort
  • Increases the lifespan of the shoe
  • Prevents hotspots and dead toenails
  • Provides stability and support to your foot

5 Downsides of a Poorly Fitted Shoe

  • Decreases running performance
  • Causes blisters and dead toenails
  • Heel lifts when running
  • Affects the durability of the shoe
  • Affects the stability and support of the shoe

Key Takeaway

Running shoes must be fitted to provide comfort. Ideally, running shoes should be snug and no movement should occur inside the shoe.

If you still have to “break-in” the shoe before it becomes comfortable, that’s not the right fitting shoe.

To find the perfect shoe size, you have to measure your feet, refer to the shoe’s conversion chart and try it on.

Wearing a poorly fitted shoe will cause discomfort and decreases your overall running performance.

Nicho Mauricio

Running wasn't always my favorite sport. I was a CrossFit athlete and I loved every bit of it. But since the pandemic began, I was forced to stay away from the gym and train at home instead. Things got boring. That's when I decided to trail run with my friends. I instantly got hooked. So I started training and researching all things running. As a beginner, I want to buy only the best running gear and do only the best practices. This blog is where I share what I've learned in my journey and my experiences as a runner.

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