How to Find Your Sneaker Size Across Nike, Adidas and New Balance

Updated October 2026 · Evergreen guide

Ordering sneakers online, especially on resale platforms with limited returns, means getting the size right the first time. The trouble is that a "10" from one brand isn't always a "10" from another, and even models from the same brand can fit differently. Here's how to find your true size and adjust for each brand.

Step 1: Measure your foot in centimeters

Your foot length in centimeters is the most consistent number you can use, because most brands list a "cm" or "JP" size on the label and in their size charts.

1. Measure in the evening, when feet are slightly larger after a day of walking.
2. Wear the type of socks you'd normally wear with sneakers.
3. Stand on a sheet of paper with your heel against a wall.
4. Mark the tip of your longest toe (not always the big toe).
5. Measure from the wall to the mark in centimeters. Measure both feet and use the larger one.

Note your foot width too: if your feet are wide, that affects which models will fit, not just which size.

Step 2: Read the size label

Look inside the tongue or the upper of a pair that fits you well. Most labels list several systems:

• US (separate men's and women's scales; women's is typically about 1.5 sizes higher than men's for the same foot, but check each brand's chart)
• UK (usually a bit lower than US men's)
• EU
• CM or JP (based on foot or shoe length in centimeters)

Brands map these systems differently, so don't convert US to EU with a generic chart. Use the brand's own size chart, and compare the cm number on a pair you already own.

Step 3: Account for brand differences

Rather than relying on rumors, check each brand's official size chart and fit notes. Some general patterns collectors often discuss:

Nike and Jordan

Nike's size chart is based on foot length, and the label lists US, UK, EU and cm. Fit varies widely by model. Some performance and lifestyle models are commonly described as snug or narrow, while others are roomier. Many product pages note fit guidance ("runs small," "true to size"), so read it for the specific model.

Adidas

Adidas uses its own chart, and its EU and UK sizes include fractional steps (like 42 2/3), which can be confusing when converting. Fit also changes by model and construction: knit uppers like those on many Boost models can feel different from leather terrace models like the Samba. Our Adidas legit-check guide also covers how to read Adidas size labels.

New Balance

New Balance stands out for offering many models in multiple widths, such as narrow, standard, wide and extra wide, labeled with letters (for example, D is standard for men and B for women, with 2E and 4E being wider). If you have wide or narrow feet, New Balance's width options can solve fit problems that a size change can't. Check the width letter on the label as well as the length.

Step 4: Consider the model, not just the brand

• Materials: leather stretches a little with wear; synthetic and patent materials barely stretch at all; knit stretches more.
• Toe box shape: slim, low-profile models feel tighter than chunky ones in the same size.
• Collaborations and retros: special editions sometimes use different lasts (the form a shoe is built on) and can fit differently from the standard model.
• Purpose: running shoes are often bought slightly roomier to allow for foot swelling during runs.

Step 5: Try on when you can

Trying on the exact model at a store is the most reliable check. A good fit usually means:

• About a thumb's width (roughly 1 cm) of space in front of your longest toe
• A snug heel with little slipping when you walk
• No pressure points on the sides or top of the foot

Buying resale or online without trying on

1. Start with a pair you own that fits well, ideally the same model or a similar one from that brand, and note the cm size on the label.
2. Compare with the brand's official size chart for the new pair.
3. Read the model's fit notes and reviews, focusing on people who mention what size they wear in other brands.
4. Check the return policy. Many resale platforms don't accept returns for wrong sizes, so be extra careful. See how resale platforms work.

Half sizes and between sizes

If you're between sizes, the safer choice depends on the shoe. For snug or stiff models, sizing up a half is more common; for roomy models, your normal size or a half down may fit better. Thick socks, insoles or orthotics also need extra room, so factor them in.

Kids' and grade school sizes

Many popular sneakers also come in kids' and "grade school" (GS) sizes, which overlap with small adult sizes. Some adults with smaller feet can wear GS sizes, though materials and construction can differ from the adult version.

Quick checklist

• Measure your foot in cm, both feet, in the evening
• Use the brand's own size chart, not a generic converter
• Check width as well as length, especially with New Balance
• Read model-specific fit notes
• Confirm the return policy before buying

Once you know your cm measurement and how your favorite brands fit you, buying online gets much less stressful. Keep a note on your phone of your size in each brand and model that fits well, and use it every time you shop.