How Should Running Shoes Fit? 10 Tips To Find the Best Fit

Wearing the right running shoes isn’t just about style or brand—it’s about protecting your body from pain and injury. Ill-fitting shoes can lead to blisters, joint pain, heel discomfort, and even more serious conditions like plantar fasciitis, Achilles tendinitis, and knee pain.

Below, we’ll walk you through what a proper running shoe fit looks like, how to measure your feet, common fit issues, and 10 expert tips to make sure your next pair supports every step. Plus, we’ll share recommended shoes, answer FAQs, and help you find the perfect pair for your running needs.

Fit Check: Finding the Right Size Running Shoe

Even when wearing a top-of-the-line running shoe, you could still suffer foot pain and injuries if it doesn’t fit right. From the width to the toe fit to the top of the foot, various factors affect how your running shoe fits. Let’s take a closer look at these factors and how your running shoes should fit in each region of your foot.

Shoe Width

Your running shoes should accommodate the full width of your foot—no pinching, squeezing, or pressure points.

What to look for:

• Your foot should slide in comfortably without force.
• You shouldn’t feel pressure along the outer edges.
• Toes shouldn’t feel cramped or overlap.

Width fit test:

• Remove the insoles and place them flat on the floor.
• Stand naturally on top of them.
• If your foot spills over the edges, the shoe is likely too narrow.

Ideal fit characteristics:

• Enough space for your toes to spread naturally.
• No bulging or pinching on the sides.
• Prevents friction-related issues like blisters or calluses.

Toe Fit

The toe box should give your toes enough room to move but not so much space that your foot slides around.

What to look for:

• About a thumb’s width of space from the tip of your longest toe to the front of the shoe.
• Natural toe splay without pressure or cramping.

Why it matters:

• Helps prevent injuries like hammer toes, bunions, or black toenails.
• Encourages better push-off and balance during your stride.
• Reduces pain during downhill or long-distance runs.

Midsole Fit

The midsole is the heart of the shoe’s cushioning system, so its fit matters for both comfort and performance.

What to look for:

• Snug underfoot without pressing uncomfortably against your arch.
• Cushion should compress slightly with each step to absorb shock.
• Midsole should contour to your foot’s natural shape.

Why it matters:

• Reduces foot and joint fatigue.
• Supports your arch and promotes better alignment.
• Helps prevent plantar fasciitis, shin splints, and related conditions.

Heel Fit

Your heel should stay locked in place—no sliding, lifting, or friction at the back of your foot.

Heel fit test:

• Lace your shoes normally.
• Stand up and gently lift your heel.
• If it slips or rubs, the fit is too loose.

Fixes and tips:

• Use a runner’s loop or heel-lock lacing to reduce slipping.
• If slipping persists, try a smaller size or a shoe with a more structured heel counter.

Why it matters:

• Prevents blisters and irritation on your Achilles.
• Improves overall foot stability.
• Promotes a confident stride, especially on uneven terrain.

Top of the Foot

The top of the shoe, or vamp, should comfortably hug your foot without creating pressure.

What to look for:

• Snug fit without tightness or pinching.
• Freedom to wiggle toes and shift your weight comfortably.

Warning signs of poor fit:

• Red marks or indentations when shoes are removed.
• Numbness or tingling during activity.

Adjustment tips:

• Loosen or re-lace the midfoot area to relieve pressure.
• Choose higher-volume shoes if you have high arches or thick feet.

10 Tips For Finding the Best Fit

Choosing the right shoe is only part of the equation. Ensuring a proper fit requires a few more steps before, during, and after trying on your running shoes. Here are 10 expert-backed tips to help you find the perfect fit every time.

1. Measure Your Feet Before Buying

• Feet can change in size over time, so remeasure each time you buy new shoes.
• Use a Brannock device or ruler to measure both feet, including length and width.
• Always size to your larger foot for a more comfortable fit.
• Consult brand-specific sizing charts, as sizing can vary by brand or even style.

Disclaimer: The above charts are a reference guide to finding your closest shoe size. It’s important to remember that shoe brands and models may vary in size.

2. Wear Your Running Socks

• Always bring or wear the socks you typically run in when trying on new shoes.
• Sock thickness can affect interior shoe volume and fit.
• Compression or cushioned socks may require a half-size adjustment.

3. Fit to Your Larger Foot

• It’s common for one foot to be slightly larger than the other.
• Choosing a shoe that accommodates the larger foot helps prevent rubbing, blisters, and pain.
• Use heel grips or additional inserts if needed to adjust for the smaller foot.

4. Try Shoes Later in the Day

• Your feet swell throughout the day, especially after walking or exercise.
• Trying on shoes in the afternoon or evening better reflects real-life running conditions.

5. Leave Room for Swelling

• Even during a single run, your feet can expand with heat and activity.
• A snug but not tight fit leaves room for this natural swelling.
• There should be no pressure on the sides or top of your foot before you even start moving.

6. Learn from Your Old Shoes

• Examine your current or past running shoes for wear patterns.
• Outer heel wear can signal supination, while inner wear suggests overpronation.
• Take note of hotspots, pain points, or features you did or didn’t like.
• Use that information to inform your next purchase.

7. Match Shoes to Training Goals

• Your running style matters: casual runs, long-distance, trail runs, or speed work all benefit from different features.
• A cushioned daily trainer may not be ideal for race day.
• Matching your shoe to your routine helps optimize performance and prevent injury.

8. Adjust the Laces

• Shoelaces aren’t just for tightening—they help personalize fit.
• Try heel-lock lacing to reduce slippage, or skip eyelets if the top feels too tight.
• Runners with wide feet can try parallel lacing to reduce pressure across the foot.

9. Consider Pronation Type

• Pronation refers to how your foot rolls inward with each step.
• Overpronators benefit from stability or motion control shoes.
• Supinators need shoes with added cushioning and flexibility.
• A gait analysis from a running store or medical professional can help identify your needs.

10. Take a Test Walk

• Always walk around in your new shoes before committing.
• Try them on a treadmill or on a firm indoor surface.
• Check for secure heel fit, arch support, and comfort across all areas of the foot.
• The right shoe should feel good from the moment you put it on—no break-in period required.

Comfort Comes First

Running is more than a workout—it’s a routine, a mindset, and sometimes even a form of therapy. But the benefits of running can quickly fade if your shoes are working against you. Ill-fitting footwear can turn a morning jog into a painful ordeal, draining your motivation and putting you at risk of injury.

So, how should running shoes fit? They should hug your foot without squeezing it, offering just the right balance of structure and flexibility. Your toes should have room to spread, your heel should stay in place, and your arch should feel supported from the ground up.

At KURU, we build every shoe with heel-to-toe comfort in mind. Our TRIPLE MAX Ion is designed specifically for runners, combining a secure fit with dynamic cushion and stability. Paired with our patented KURUSOLE technology and shock-absorbing KURUCLOUD midsole, you get a shoe that supports your stride and protects your joints mile after mile.

Because when your shoes feel great, running feels even better.

Sourcing

• Cardiovascular benefits of running. Is running associated with a lower risk of all-cause, cardiovascular and cancer mortality? (November 2019)
• A cushioned midsole can reduce joint pain and injury. Systematic Review of the Role of Footwear Constructions in Running Biomechanics (March 2020)

About Us

At KURU, we're on a mission to help you Heel Better™ with footwear technology designed to relieve foot pain, so you can live a life you love. Since launching our innovative technology in 2008, we’ve received more than 39,000 five-star reviews from thousands of customers who tell us their KURU shoes helped them get back to doing what they love.

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