The Eternal Question: Nike or Adidas — Which Size Should I Order?
If you wear a medium in Nike, does that mean you're a medium in Adidas? Not necessarily. Both brands have their own fit philosophies, and understanding the differences can save you from the hassle of returns. This comparison covers apparel and footwear for men and women.
Apparel Sizing: Nike vs. Adidas
Both brands use standard US letter sizing (XS through XXL), but their fits differ due to intended use, fabric choices, and design philosophy.
Men's T-Shirts & Tops
| Size Label | Nike Chest (in) | Adidas Chest (in) | Difference |
|---|---|---|---|
| S | 35–37 | 34–36 | Nike ~1 in larger |
| M | 38–40 | 37–39 | Nike ~1 in larger |
| L | 41–43 | 40–42 | Nike ~1 in larger |
| XL | 44–46 | 43–45 | Nike ~1 in larger |
| XXL | 47–49 | 46–48 | Nike ~1 in larger |
Takeaway: Nike tops tend to run about one inch larger in the chest than comparable Adidas tops. If you're between sizes, you may need to size down when switching from Nike to Adidas.
Women's Apparel
For women's clothing, the gap is less consistent but still present:
- Nike women's styles often feature a more relaxed, performance-oriented cut.
- Adidas women's apparel (especially the Originals line) tends to run slimmer and slightly shorter in the torso.
- If you wear a Nike M, try an Adidas M or L depending on whether you prefer a looser or more fitted look.
Footwear Sizing: Nike vs. Adidas
This is where the differences are most commonly felt. Both brands use US sizing, but the physical fit of the shoe can differ significantly.
Key Differences
- Toe box: Adidas shoes (especially running and lifestyle shoes) generally have a wider toe box. Nike tends toward a narrower, more tapered front.
- Length: Nike shoes are often reported to run about a half size small. Many people who wear a 10 in Adidas find they need a 10.5 in Nike.
- Arch support: Nike's heel counters are usually more structured, which can affect how snug the shoe feels overall.
Shoe Size Comparison Guide
| True Foot Size | Recommended Nike Size | Recommended Adidas Size |
|---|---|---|
| US 7 | 7.5 | 7 |
| US 8 | 8–8.5 | 8 |
| US 9 | 9–9.5 | 9 |
| US 10 | 10–10.5 | 10 |
| US 11 | 11–11.5 | 11 |
Note: These are general tendencies based on widely reported customer experiences. Always check the specific shoe model's fit notes, as some styles vary.
Which Brand Is Better for Wide Feet?
Adidas is generally the better choice for wider feet, particularly in their running and casual lines. Nike has introduced wider width options (2E) in select styles, but availability is more limited.
Bottom Line: How to Choose the Right Size
- Always measure your chest, waist, and hips before buying apparel from either brand.
- For shoes, measure your foot length and compare to each brand's size chart — don't assume your size transfers directly.
- Check model-specific reviews: the Nike Air Max fits differently from the Nike Free Run, for example.
- When unsure, size up — especially for footwear where going too small is more uncomfortable than going slightly large.