The Ultraboost 1.0 is the comfort cruiser a lot of people reach for first — but before you buy, the question is the usual one: does the Ultraboost 1.0 run true to size?
We sell the Ultraboost at West Coast Deals, so I've had plenty of pairs in hand. Here's the straight answer, grounded in the broad consensus, with a note for those of us with wider feet.
Does the Ultraboost 1.0 run true to size? The short answer
For most people, the Ultraboost 1.0 runs true to size. The Primeknit upper is stretchy and sock-like, with generous room at the big toe once it breaks in. If you have a wider foot, go up half a size — and here's the important part: the limiter isn't the knit, it's the rigid TPU midfoot cage that wraps the arch. That cage doesn't give the way the knit does.
How it fits, and why width is the real question
I wear a US 11 and have a wider-than-average foot. At true to size the knit was comfortable across the toes, but I could feel the plastic cage pressing in at the midfoot — the structure that locks your arch in place also caps how wide the shoe can go. Half a size up relaxed that pressure without making the shoe feel sloppy, because the external heel counter and the cage still lock the foot down. If your feet are standard width, your normal size is the move; the knit handles the rest. Thick-sock wearers should also lean half up.
What the Ultraboost 1.0 is
Despite the "boost" name and running-shoe looks, the Ultraboost 1.0 today is really a cushioned lifestyle cruiser — it's heavier and softer than a performance racer, built for all-day comfort rather than speed. The build is a knit Primeknit upper over a full-length Boost midsole, with a Torsion TPU cage at the midfoot and an external heel counter for lockdown.
How it compares to other adidas runners
If you're cross-shopping, the Ultraboost is the plush, casual end of the spectrum. The race-bred Adizero models fit narrower and more locked-in — see our Adizero Evo SL sizing guide and the max-cushion Hyperboost Edge sizing guide for how those differ. Our adidas running shoes comparison puts the whole lineup side by side.
Final verdict
The Ultraboost 1.0 is true to size for standard feet. Wider feet — like mine — should go up half a size to clear the TPU cage, and thicker-sock wearers should do the same. Give the Primeknit a few wears to settle; it loosens and gets more comfortable as it breaks in.
We sell the Adidas Ultraboost 1.0 at West Coast Deals, authenticated in-house and shipped from our Portland, Oregon warehouse. Browse current Ultraboost colorways and sizes, including the Triple White Ultraboost 1.0 and the White/Black Ultraboost 1.0.
— Anthony from West Coast Deals