Short answer
The Adidas Ultraboost 5X delivers a True to Size (TTS) experience, featuring an uncaged mono-yarn Primeknit upper that prioritizes comfort and lateral relief. While it lacks a snug, rigid midfoot cage, the stretchy material creates a sock-like fit that accommodates high-volume feet and promotes natural toe splay in its generously roomy toe box.
Runs true to size
Cross-sizing: what size to buy
Find a shoe you already own and read across to the Adidas Ultraboost 5X size to buy.
| Reference Shoe | US | EU | ||
|---|---|---|---|---|
| Your usual | Buy | Your usual | Buy | |
| Nike Air Force 1 | 10 | 10.5 | 44 | 44.7 |
| Nike Pegasus 41 | 10 | 10 | 44 | 44 |
| Adidas Samba (OG) | 10 | 10 | 44 | 44 |
| Vans Old Skool | 10 | 10.5 | 44 | 44.7 |
-
Nike Air Force 1
Your usual Buy US 10 10.5 EU 44 44.7 -
Nike Pegasus 41
Your usual Buy US 10 10 EU 44 44 -
Adidas Samba (OG)
Your usual Buy US 10 10 EU 44 44 -
Vans Old Skool
Your usual Buy US 10 10.5 EU 44 44.7
Fit Notes
- Nike Air Force 1
- The Nike Air Force 1 is notoriously oversized compared to standard performance models. To match the Ultraboost 5X's performance-oriented length, most users should size up at least 0.5 from their AF1 size to ensure adequate longitudinal clearance.
- Nike Pegasus 41
- Both shoes adhere to a standard performance length and generally fit True to Size. While the Pegasus 41 provides a tighter mesh lockdown, the Ultraboost 5X's uncaged Primeknit feels significantly more voluminous in the forefoot despite sharing the same length baseline.
- Adidas Samba (OG)
- Internal length is consistent within the Adidas brand. However, if you typically size up in the Samba just to compensate for its narrow leather build, you should revert to your true size for the 5X, as the elastic knit is much more forgiving for wider foot profiles.
- Vans Old Skool
- Using Vans as a lifestyle baseline, users frequently find that a 0.5 size increase in the Ultraboost 5X provides a better performance fit. This adjustment accounts for the 5X's performance shaping and allows for the natural foot swelling associated with long-duration wear.
Sizing FAQ
Does the Adidas Ultraboost 5X run true to size?
Yes, the consensus is that the shoe is True to Size (TTS) for the majority of users. However, specific foot shapes may require adjustments: users with a 'Greek foot' (second toe longer) should consider a half-size increase to gain vertical and longitudinal clearance, while those with extremely narrow feet might size down 0.5 to improve heel lockdown.
Is the Adidas Ultraboost 5X good for wide feet?
Absolutely, it is cited as one of the most accommodating shoes for wide feet currently available. The combination of an uncaged design and highly elastic Primeknit allows the foot to expand naturally, while a wide forefoot measurement (96.2 mm) and minimal toe box taper facilitate essential toe splay.
How is the arch support on the Adidas Ultraboost 5X?
The Ultraboost 5X is a neutral shoe that provides moderate arch support through an internal X-Torsion system. While this rigid midfoot shank prevents excessive twisting and adds stability, the shoe is not designed to correct severe overpronation.
Specs & Sizing
| Weight | 275 g |
|---|---|
| Retail price | $180 |
| Price on Amazon | $99 - $144 |
| Release year | 2022 |
| Upper | Engineered mesh / adidas Primeknit with adaptive, sock-like fit; contains at least 20% recycled content |
| Midsole | Light BOOST foam – Adidas's lightest and most responsive Boost formulation to date |
| Outsole | Continental™ Rubber for high durability and reliable grip on wet/dry surfaces |
| Technologies | Light BOOST, TORSION System, Primeknit Upper, Continental Rubber Outsole |
| Fit & sizing | Runs true to size for most users; order your regular shoe size |