How to Find Your Shoe Size Online

Ordering shoes online comes with one challenge that trying them on in-store doesn't: you can't feel the fit before you buy. Getting your size right from the start saves time, avoids unnecessary returns, and helps you shop with more confidence.

This guide walks you through how to measure your feet at home, how to read a size chart, and what to keep in mind when choosing between sizes — so you can make a more informed decision before adding to cart.

1. Why Shoe Size Matters More When You Shop Online

In a physical store, you try on a shoe, take a few steps, and know right away if it works. Online, you rely on measurements and size charts — which vary significantly between brands, models, and countries.

The same numerical size can fit differently depending on the last shape (the 3D form used to build the shoe), the materials used, and how a particular model is designed. A size 9 in one brand may feel like a 9.5 in another. That's why knowing your actual foot measurement — not just a number you've always used — is the most reliable starting point.

2. How to Measure Your Feet at Home

You only need a few household items: a sheet of paper, a pencil or pen, a ruler or measuring tape, and a hard flat surface.

1. Place the paper on a hard, flat floor. Avoid carpet, which can shift your foot position and skew the result.
2. Stand on the paper with your heel touching a wall or a straight edge.
3. Trace around your foot as closely as possible. Keep the pen vertical — angling it inward will make the tracing smaller than your actual foot.
4. Mark the longest point from heel to the tip of your longest toe. Note that the longest toe is not always the big toe.
5. Measure the length from the heel mark to the toe mark in centimeters or inches.

Measure at the end of the day. Feet swell slightly from walking and standing throughout the day, so an evening measurement gives you a more realistic size for everyday wear.

3. Measure Both Feet

Most people have feet that differ slightly in size — this is normal. Always measure both feet and use the larger measurement as your reference when selecting a size. If the difference is significant (half a size or more), prioritize comfort for the larger foot. Some people choose to use an insole on the smaller side to compensate.

4. Compare Your Measurement with the Size Chart

Once you have your foot length in centimeters, look up the size chart for the specific product you're considering. At Fuix US, size information is available on individual product pages — check there for the most accurate reference for each model, as sizing can vary.

Size charts are a guide, not a guarantee. Fit may vary by brand and model even within the same numerical size. Use the chart as a starting point, then factor in the other considerations below.

5. Understand EU, US, and UK Sizing

Shoes are produced and labeled in different sizing systems depending on their origin and target market. The table below offers a general reference for converting between the most common systems. These values are approximate — always check the size chart on the specific product page before ordering.

Values are approximate and vary by manufacturer. Always check the size chart on the product page before ordering.

6. Account for Brand and Model Differences

Size charts get you close, but fit depends on more than numbers. Key factors include:

• Last shape: A narrower last produces a tighter fit; a wider last gives more room in the toe box. Brands typically describe this in product notes on the product page.
• Materials: Full-grain leather often stretches slightly with wear, while synthetic materials and knit uppers tend to hold their shape. Some knit uppers adapt more readily to foot shape.
• Heel counter: A firm heel counter keeps the foot positioned more precisely; a softer one allows slightly more movement.
• Shoe category: Running shoes are often designed with extra length at the toe (roughly a thumb's width) to allow for foot movement during activity. Casual shoes and dress shoes often fit closer to actual foot length.

If you've worn a particular brand before and know how it fits you personally, that experience is a useful reference. For a new brand or model, check the available product details and any sizing notes on the product page to see whether specific fit guidance is provided.

7. Think About Socks and Intended Use

The thickness of the socks you plan to wear affects how a shoe fits. Athletic shoes used with thick sports socks will feel noticeably tighter than when tried with thin socks. If you're buying shoes for running, gym use, or hiking, factor in the sock thickness you'll actually use during activity.

Intended use also matters for sizing. Shoes worn for high-impact activity benefit from a bit of extra length at the toe to prevent the foot from sliding forward. For casual daily wear or light use, a closer fit is usually fine.

8. What to Do If You Are Between Sizes

If your foot measurement falls between two sizes, a few questions can help guide your decision:

• Is it for athletic activity? Go up half a size to allow room for foot movement during use.
• Is the upper material stiff or structured? Consider going up half a size, as the material is unlikely to stretch significantly over time.
• Do you have a wider foot? Going up half a size may provide slightly more width as well as length in some models.
• Is it for light, casual use? Sizing down half a size may be comfortable if you prefer a more fitted feel.

When in doubt, check the product page for any sizing notes or fit information provided for that specific model.

9. Checklist Before You Order

• ✓ I have measured both feet and noted the larger measurement
• ✓ I have checked the size chart on the product page for this model
• ✓ I have identified which sizing system the product uses (EU / US / UK)
• ✓ I have considered the socks I plan to wear
• ✓ I have checked any available sizing notes or fit information on the product page
• ✓ I have checked the return and exchange conditions for this order

10. Find Your Next Pair at Fuix US

Ready to shop? Browse the full shoe selection at Fuix US, including a wide range of sneakers in various styles and sizes. Product pages include available sizes and, where provided by the brand, specific size guidance for that model.

For tips on choosing everyday sneakers, see our Everyday Sneakers Guide. More sizing resources are available in the Size & Fit section of our buying guides.

Fit may vary by brand and model. Size charts are provided as a reference only. Check each product page for current size and color availability. Return options may vary depending on the order and product.