Where 10" sits on the EN scale
EN ISO 21420 sizes are one inch of circumference apart, so a 10-inch hand is exactly size 10: the table’s 254 mm reference with a typical length of 204 mm.
Size 10 is XL on unisex lines and XXL on women’s lines, which are cut a letter smaller for the same hand.
10" × 25.4 = 254 mm round flat width ≈ 254 ÷ 2.42 = 105 mm (men)
Sport, ride and winter
Goalkeeper gloves add an inch: 10" rounds to 10 and becomes size 11 (Reusch’s half-size chart: 10). Alpinestars’ men’s chart puts 25.4 cm at 3XL, on the edge of a band: try both. Hestra winter gloves are a 10 bare, 10 over a 1 mm liner.
Boxing gloves at 10" are youth sizes (Rival youth 8–10 oz) or below the adult hand bands.
One half size down, 9.5" is EN 9 and goalie 11. One up, 10.5" is EN 11 and goalie 12.