Last Updated on October 3, 2026
Quick answer: Which shoe calculator should I use? Start with the Adult Shoe Size Calculator if you know your foot length. Use the country converter for U.S., U.K. and EU sizes. If you already know your size in one running brand and are switching brands, use the running shoe brand converter. For sneakers, boots, sandals and other lifestyle shoes, use the casual shoe size converter. Parents can use the Kids Shoe Size Calculator.
Shoe sizing gets confusing because length, width, country systems and brand fit are separate problems. One calculator cannot answer all of them well. This page brings BestWalkingFeet’s sizing and fit tools into one place so you can start with the question you are actually trying to solve.
Choose the Right Shoe Size or Fit Tool
If you want to… | Use this tool | What it does |
|---|---|---|
Find an adult shoe size from a foot measurement | Uses foot length to estimate adult shoe size and includes sizing charts. | |
Convert U.S., U.K. and EU shoe sizes | Converts between common international sizing systems. | |
Switch from one running shoe brand to another | Estimates the closest size when changing running shoe brands and lets you include standard, narrow, wide or extra-wide fit. | |
Switch between casual or lifestyle shoe brands | Compares sizing across sneakers, boots, sandals, dress shoes and comfort-shoe brands. | |
Find a child’s size from a measurement | Uses foot measurement to estimate children’s shoe size. | |
Convert children’s sizes between countries | Compares children’s sizing across U.S., U.K. and international systems. | |
See shoe size by foot length in inches or centimeters | Shows common shoe sizes beside foot length in inches and centimeters. | |
Figure out whether width is the problem | Explains how to measure foot width and compare it with men’s and women’s width charts. | |
Find a shoe based on fit, gait and activity | Narrows shoe choices using your activity, support and fit needs. |
Adult Shoe Size Calculators
If you are starting with a foot measurement, use the Adult Shoe Size Calculator and Sizing Chart. It is the simplest starting point when you do not already know your size. Measure the longer foot, enter the length and use the result as a starting estimate rather than an absolute rule.
If you already know your shoe size but need the equivalent in another country, use the Shoe Size Converter by Country. That is the better tool for questions such as “What is a men’s U.S. 10 in the U.K.?” or “What EU size is a women’s U.S. 8?”
For a simple lookup instead of an interactive calculator, the Shoe Size by Foot Length in Inches and Centimeters page puts common foot lengths and shoe sizes side by side.
Switching Shoe Brands? Use the Brand-to-Brand Converter
A size 10 does not always feel the same from one brand to another. Toe-box shape, heel fit, overall volume and the last used to build the shoe can all change how a size feels. The Shoe Size Converter Between Brands is designed for that problem.
The converter lets you select the brand you currently wear, your usual U.S. size and the brand you want to try. It also lets you identify your current fit as standard, narrow, wide or extra wide. That width selection does not measure your foot width for you, but it gives the converter more context when it explains the likely fit.
If you need brand-specific detail before ordering, use our shoe brand sizing and fit guide. We also maintain individual sizing guides for major brands including Hoka, Asics, New Balance, Nike and Vionic.
Kids Shoe Size Calculators
Children’s sizing changes quickly, so measuring the foot is more useful than relying only on age. The Kids Shoe Size Calculator From Measurement is the main tool for turning a child’s foot length into a starting shoe size. The Kids Shoe Size Country Converter is better when you already know the child’s size and need to convert it between sizing systems.
If you are trying to understand the overlap between older children’s sizes and women’s sizes, see Kids vs. Women’s Shoe Sizes. For age-based averages, use our average kids shoe size by age chart as a rough reference only. A direct foot measurement is more useful for an individual child.
What if the Length Is Right but the Shoe Still Feels Tight?
That is often a width or shape problem rather than a length problem. If your toes feel compressed, the ball of your foot presses against the sides or you regularly size up just to get more room, use our wide-feet measurement guide. It includes men’s and women’s width charts and explains how to measure the widest part of your forefoot.
Also separate overall width from toe-box shape. A shoe can be sold in a wide size and still taper at the toes. A shoe with a roomy toe box can give your toes more space while remaining secure through the heel and midfoot. If toe room is your main problem, compare our best wide toe-box shoes. If you need labelled wide and extra-wide sizes, see the best wide shoes for walking. If standard wide sizes still pinch, compare our best 4E, 5E and 6E shoes for very wide feet.
Fit Tools Beyond Shoe Size
Shoe size is only one part of fit. If you are choosing running or walking shoes, your gait, support preference, activity and foot shape also matter. Our running gait guide and calculator helps explain how your foot moves, while the Free Shoe Finder uses several fit and activity questions to point you toward suitable shoe types.
If you are shopping specifically for work, standing or walking shoes and need extra width, our wide work shoe guide and wide walking shoe guide compare current models with wide and extra-wide options.
How to Measure Before Using a Shoe Calculator
Measure both feet while standing, because your foot spreads under your body weight. Do it later in the day if possible, especially if your feet tend to swell. Measure from the back of the heel to the longest toe, not automatically to the big toe. Use the longer foot when the two measurements differ.
For width, measure across the widest part of the forefoot. Do not assume that buying a longer size is the right way to create more room. A shoe that is too long can cause heel slip while still leaving the toe box or forefoot too narrow.
Why Shoe Calculator Results Are Estimates
Shoe sizing is not perfectly standardized. Two shoes marked with the same size can fit differently because brands use different lasts and even models within the same brand can vary. Socks, orthotics, foot swelling and the intended activity can also affect fit.
Use these calculators to narrow the range, then check the current manufacturer’s size chart and return policy for the exact shoe. If you already own a model that fits well, the brand-to-brand converter is usually more useful than starting from a generic conversion chart.
