Adidas: Manufacturer advice
There is no verified brand-wide fit offset or reproducible wearer distribution in this dataset. Size labels and measured foot length are different quantities. A chart does not establish the fit of every model.
NMD_R1
Adidas recommends the usual size for NMD_R1. The sock-like upper can feel close around the foot even when the length label is appropriate; this does not establish that the model runs short. Use the official chart, then check pressure around the instep and the exact upper construction. The NMD_R1 is presented here as a casual sneaker, not a performance running shoe.
Stan Smith
Adidas describes adult Stan Smith sizing as true to the usual size. Its sizing guide distinguishes upper materials, so a familiar size is a starting point rather than proof that every edition feels identical. Use the men’s or women’s US column of the unisex chart and check the product’s own guidance. This is a lifestyle sneaker, not a running-shoe recommendation.
Ultraboost 1.0
The official Ultraboost 1.0 pages disagree by product code: JQ0826 advises half a size up, while JR1986 advises the usual size. Check the code on the pair you intend to buy before applying either suggestion. The shared Adidas chart supplies label correspondences; it cannot resolve this product-specific difference. These notes cover 1.0, not every Ultraboost generation.