Adidas Ultraboost 1.0 Shoes Sizing Guide: Does It Run Small or True to Size?

Fit Notes

Nike Air Force 1

The Nike Air Force 1 is notorious for running a half-size large due to its wide, highly voluminous leather toe box. Conversely, the Ultraboost 1.0 features a highly compressed vertical ceiling. Wearers must size up a half-size from their standard shoe size (or a full size up from their AF1 size) to compensate for this severe drop in vertical space and prevent toe crowding.

Nike Dunk Low

The Nike Dunk Low serves as an industry standard for a true-to-size (TTS) fit with standard midfoot width. The Ultraboost 1.0 fits much tighter around the perimeter due to its rigid midfoot TPU cage and non-stretch engineered mesh collar. Sizing up a half-size ensures easier entry through the collar and provides necessary lateral relief from cage pressure.

Adidas Samba

The Adidas Samba utilizes a flat, narrow indoor soccer last where users often size up strictly to compensate for a tight horizontal width. In contrast, the Ultraboost 1.0 offers better lateral flexibility via Primeknit, but demands a half-size up due to vertical volume constraints caused by thick Boost cushioning and a rigid, non-stretchy ankle collar opening. Sizing up 0.5 accommodates this internal volume while retaining proper heel cup containment.

Yeezy 350 V2

Both models are built by Adidas on a similar design language featuring full-length Boost and a highly restrictive, low-volume Primeknit upper. Because the Yeezy 350 V2 features an identical sloped toe box that already forces users to size up a half-size from their true anatomical measurement, you can buy the exact same size in both models for an identical, one-to-one fit.