Sizing

X-Large: Base of palm to tip of middle finger length: 8".
Large: Base of palm to tip of middle finger length: 7-1/2".
Medium: Base of palm to tip of middle finger length: 7".
Small: Base of palm to tip of middle finger length: 6-1/2"".
Youth Large: Base of palm to tip of middle finger length: 6".
Youth Medium: Base of palm to tip of middle finger length: 5-1/2".
Youth Small: Base of palm to tip of middle finger length: 5".

If unsure, size up for a looser fit or size down for a tighter fit.
For the complete size chart, please see the second image on the product listing.