Nike Cortez 23 Sizing Guide: Does It Run Small or True to Size?

Fit Notes

Nike Pegasus / Vomero Series

Flagship performance daily trainers like the Pegasus and Vomero series are built to accommodate dynamic muscular splay during high-impact athletic use. The Cortez 23 functions on a more streamlined, standard-to-narrow lifestyle template. Regarding the length vs. width compensation factor: if you typically buy a US 10 in performance running lines strictly to gain extra forefoot width, you should return to your true length by purchasing a half-size down (US 9.5 / EU 43.5) in the leather Cortez 23, as its updated, wider toe box footprint removes the need to overcompensate with extra shoe length. Standard or narrow-footed users should remain true to size.

Nike Structure 26

The Structure 26 is a highly structured, stability-centric daily trainer designed with a accommodating layout to secure overpronating feet. The Cortez 23 mirrors this emphasis on mechanical control through its rigid heel counter and foam wedge platform. When translating sizes, users accustomed to the spacious midfoot baseline of the Structure 26 can stick to their normal size for a casual fit, or size down a half size if they have narrow feet and favor a precise, low-volume profile that relies on the leather Cortez's re-engineered forefoot space.

Nike Zoom Prevail

The Zoom Prevail is widely documented as running short and exceptionally narrow, making it highly restrictive for broad foot shapes. If a US 10 in the Zoom Prevail represents your actual linear foot size, selecting a US 10 in the Cortez 23 provides a highly balanced fit. Applying the width compensation directive: if you are a true size 9.5 but purchased a size 10 in the narrow Zoom Prevail solely to avoid lateral pressure, you should return to your true length of 9.5 in the Cortez 23, as the leather variant's optimized toe box geometry provides more natural lateral relief than the narrow performance shoe.