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How to Choose Sneakers Size Online
Take fresh foot length and width measurements, use the calculator for a starting size, then open the brand chart and compare your foot length in centimetres with the brand column, not just the size label. Add half a size for running use, check whether the model runs narrow or roomy in reviews, and read the return policy before you order. When you fall between sizes, order the size that fits your use, and consider ordering two sizes if returns are free.
Start with fresh measurements, not your usual size
Your usual size is a starting hint, not a measurement. Feet change with age, activity and weight, and brands grade their sizes differently, so a size that fit last year may not fit this year. Measure your foot length and width in the afternoon, in the socks you plan to wear, and use the longer foot. Enter the numbers in the calculator for a starting size, then keep the foot length in centimetres handy, because many brand charts list centimetres as the primary column.
Write the numbers down before you shop, so you can compare them with each brand chart without guessing. A foot length of 25.4 cm is a concrete fact you can match to a row, while a memory of being a size 8 is not, because that size meant something different at the last brand you bought. If you have not measured in the past year, measure again before you order.
Read the brand chart, not just the size label
Open the size chart on the product page and find the row where your foot length in centimetres falls. Compare your foot length with the brand column, and check whether the brand lists foot length or insole length. Insole length is longer than foot length by the toe room built into the shoe, so if the brand lists insole length, leave about a thumb width of room in the number rather than matching it exactly.
Check the width column too, if the brand gives one, and note whether the model comes in narrow, regular, wide or extra wide. Some product pages also carry a fit note, such as runs narrow or runs true to size, which tells you whether to stay with your starting size or move half a size. For a general method that works across shoe types, see how to choose shoe size online.
Use reviews to learn how the model fits
Reviews are useful for fit, not for size labels alone. Look for repeated comments about the model running narrow, running long, having a tight toe box, or needing half a size up for running. One review saying the shoe runs small may be an outlier, but twenty reviews saying the same thing is a pattern worth following. Pay most attention to reviewers who mention their foot length, width or arch, because their feet may match yours.
Be careful with reviews that only say the shoe is true to size, because that phrase means the shoe matches the reviewer's usual size, which may not match yours. Combine the review pattern with your measured foot length and the brand chart, and let the measurements win when they disagree with a review. If reviews consistently say the model runs narrow and your foot is wide, move up half a size or choose a wide version.
Plan for running use before you order
If you plan to run in the sneakers, add the running rule before you order. Start half a size up from your everyday sneaker size, because feet swell and slide forward during a run. That extra half size protects your toenails on long runs and keeps the toe box roomy when your feet are warm. If the brand chart already builds extra room into its running sizes, the fit note will usually say so, but most brands do not, so apply the rule yourself.
Also consider the socks you will run in. A thick cushioned running sock takes up more room than a thin everyday sock, so measure and order with the running sock on your foot. If you use an aftermarket insole or an orthotic, check whether it adds height inside the shoe, because a thicker insole can make a well sized shoe feel tight across the top of the foot.
Check the return policy before you pay
Even with careful measuring, an online order can miss, so read the return policy before you pay. Check how many days you have to return, whether returns are free, whether worn shoes can be returned, and whether an exchange is faster than a refund. Some sellers allow a short indoor trial, which lets you walk around the house and check the fit before you decide.
When you fall between sizes and returns are free, ordering two sizes and returning one is often the cheapest way to get the fit right. When returns cost money or take weeks, spend the extra time on the brand chart and the review pattern instead, and order the size that fits your main use. Keep the box and the receipt until you have worn the pair indoors and checked the fit, because a missing box can complicate a return. For why sizes differ at all, see why shoe sizes vary between brands.
Sneakers sizing tool
Use the Sneakers Size Calculator
Start with your measured foot length and width in the calculator, then take that starting size to the brand chart before you order.
Frequently Asked Questions
Should I order my usual size when buying sneakers online?
Use your usual size as a hint only. Measure your foot length first and compare it with the brand chart, because brands grade sizes differently.
How do I know if a sneaker model runs narrow online?
Read the brand fit note and look for repeated reviews saying the model runs narrow, has a tight toe box, or needs a wide fit.
Should I size up for running sneakers bought online?
Yes, usually half a size up from your everyday sneaker size, because feet swell and slide forward during a run.
What should I check in the return policy?
The return window, whether returns are free, whether worn shoes can be returned, and whether an exchange is faster than a refund.
Is it better to order two sizes online?
If returns are free, ordering two sizes and returning one is often the fastest way to find the right fit. If returns cost money, rely on the brand chart instead.