The Truth About Running Shoe Sizing: Why Bigger Is Better

Here's something most new runners don't expect: your running shoes should be bigger than your everyday shoes. Not just a little bigger. We're talking a half size to a full size larger than what you'd normally wear. Sounds strange, right? But there's solid reasoning behind it, and understanding proper running shoe sizing can keep you movving without the pain that sidelines so many runners.

How Much Space Should Running Shoes Have?

When trying on running shoes, there should be about a thumb's width of space between your longest toe and the front of the shoe (roughly 1 centimeter). To someone used to snug-fitting everyday shoes, this can feel surprisingly roomy. But for running, it's exactly right.

Your feet naturally expand during runs, both in length and width. The further you run, the more your foot will naturally expand. That extra space isn't wasted. It's working space for your feet to do what they need to do.

When you run, especially uphill, your foot flexes and your toes push forward with each stride. Without adequate room, your toes jam into the front of the shoe repeatedly. Over miles, that adds up: black toenails, bruised toes, blisters, and discomfort that can cut your run short.

Should You Go Half Size or Full Size Up in Running Shoes?

Most runners do well with shoes a half size larger than their normal shoe size, though some runners find that a full size larger works better. If you run primarily in the afternoon or evening when your feet are at their largest, or if your feet tend to swell significantly, consider going up a full size.

Here's where it gets less straightforward: sizing isn't universal. Shoe sizes aren't consistent within brands, meaning one model fits differently than another even if they're both made by the same company. A size 9 in one brand might feel completely different from a size 9 in another. This is why trying shoes on, ideally with a run around the store, matters more than the number on the box.

Running Shoe Fit and Injury Prevention

Proper shoe fit isn't just about comfort. It's about keeping you movving. About three-fourths of runners are wearing the wrong size shoe, mostly too small.

Getting the sizing wrong can put pressure on plantar nerves, causing numbness, tingling, and pain that can mimic plantar fasciitis. Wrong-sized shoes can also affect your knees, hips, and back. Meanwhile, shoes that are too loose create instability, leading to blisters and lack of support.

The right fit helps your foot move naturally. Your foot needs to splay and flex to absorb impact and propel you forward. When shoes fit properly, they work with your body's natural mechanics.

At MOVV, we engineer footwear specifically to reduce running-related injuries and work with your body's natural movement. Our unique forefoot design allows your toes to spread into their natural position, giving you the power to push off effectively.

How to Find the Right Running Shoe Fit: Step-by-Step Guide

Start by getting your feet measured: every time you buy new shoes. The size and shape of our feet change over time. Don't assume you know your size based on what you wore years ago or even last season.

Measure later in the day when your feet are at their largest, and wear the socks you plan to run in. Thicker socks take up more room; thinner socks give you more space. These details matter.

Most people have one foot slightly larger than the other. Always fit shoes to your larger foot. You can adjust lacing or add an extra sock on the smaller foot if needed.

Key Fit Points to Check

When trying shoes on, check these key points:

The heel and midfoot should feel snug and secure. Your heel shouldn't slip as you walk or run.

The toe box should allow your toes to spread naturally and move freely. You should be able to wiggle them without restriction. MOVV's Nostara running shoes feature a uniquely designed toe box that allows your toes to spread into their natural position.

The overall feel should be supportive without being tight. The shoe should feel like it's working with your foot, not fighting it.

Walk around. Better yet, run in them if the store allows it. Check that your heel doesn't slip and that nothing pinches or rubs uncomfortably. Trust what your feet tell you over what the size label says.

Running Distance and Shoe Sizing Considerations

The length of your runs can influence sizing decisions. Some runners find a half size works for shorter distances like 10K, but need to go up a full size for half marathons or longer. The longer you're on your feet, the more your feet expand and the more that extra space matters.

Trail runners might need even more room than road runners, especially for steep downhills where your foot slides forward in the shoe with each step.

Signs Your Running Shoes Don't Fit Properly

Your body will tell you when something's off. Here are the key warning signs:

Shoes That Are Too Small

Blisters on your toes mean shoes are too tight. Bruising indicates insufficient toe room. If your toenails turn black or fall off after long runs, your shoes are definitely too small. Numbness or tingling in your toes could mean shoes are too narrow or laced too tightly.

Shoes That Are Too Big

On the flip side, if your heel is slipping despite proper lacing, your shoes might be too big. The key is finding that balance, snug where you need support, roomy where your foot needs to move.

Finding Your Perfect Running Shoe Fit

Forget what the number says. Proper fit trumps everything else. Numerical size doesn't matter at all. Your feet will be healthier and happier if you choose running shoes that actually fit.

The half-size-bigger rule is a starting point, not an absolute. Some runners need more space; some need less. What matters is that thumb's width of room in front, a secure heel, a snug midfoot, and enough width for your foot to spread naturally.

Getting this right means fewer injuries, more comfortable runs, and the freedom to keep movving. Your shoes should support your running, not hold it back. Take the time to find the fit that works for your feet, your stride, and your goals. Because when your shoes fit right, you can focus on what really matters: the run itself.

Ready to Find Your Perfect Fit?

Explore MOVV's collection of Scandinavian-engineered running shoes designed with injury prevention and natural foot movement in mind.