UK (UK) to US Men's (US M) Conversion

UK

UK shoe sizes are based on the barleycorn system — one barleycorn equals one third of an inch (8.47 mm) — where the size represents last length in barleycorns minus a fixed offset. UK Men's sizes typically run 0.5 to 1 size below the equivalent US Men's size for the same foot (UK 9 ≈ US 9.5). UK Women's sizes run approximately 2.5 sizes below US Women's. The system predates metric standardisation and remains in official use in the United Kingdom alongside EU sizing on product labels.

US Men's

US Men's shoe sizes follow the Brannock system, where the size is derived from the last length in inches using the formula: size = (last length in inches × 3) − 22. A US Men's size 10 corresponds to a last approximately 10⅔ inches (27.1 cm) long. The Brannock Device — the familiar metal foot-measurement tool in shoe stores — was invented by Charles Brannock in 1925. US Men's sizes typically run from 6 to 16, with each half-size increment corresponding to approximately 4.23 mm of foot length.