Measure hand circumference (around the knuckles) and hand length (base of palm to tip of the middle finger), then map to the brand chart.
Nike: Use Nike’s official American Football Gloves size chart (Men’s S–3XL with both hand-circumference and hand-length ranges; Women’s and Youth charts included).
adidas: Follow adidas’ glove measurement guidance (measure palm circumference, round up to the next inch and add 1 to get your glove size). adidas glove product pages show numeric sizes (typically 5–12 including half sizes) and a “Size Chart” overlay.
Under Armour: Measure hand length (from the base of the palm to the tip of the middle finger). Compare your measurement to the Under Armour size chart, which covers Men’s, Women’s, and Youth sizes.
NIKE — American Football Gloves size chart: https://www.nike.com/size-fit/american-football-gloves ADIDAS — American Football Gloves guidance: https://www.adidas.com/us/soccer-gloves
UNDER ARMOUR — Glove Sizing: https://www.underarmour.com/en-us/t/size-guide.html