XL ski gloves are designed for hand circumferences between 9.5 and 10.5 inches, measured around the widest part of your palm (excluding the thumb). If you've always worn large gloves in casual wear but feel tightness across your knuckles or fingertips when gripping a ski pole, moving up to XL is likely the right call.
Getting this right matters more than you'd think. Gloves that are too tight restrict blood flow to your fingers, which is actually one of the most common reasons people get cold hands on the mountain — even with premium insulation. On the flip side, if an XL glove is too loose, you lose that critical air gap that traps warmth, and your dexterity suffers when working zippers or adjusting bindings.
If you're between sizes, size up slightly and make sure to try them on with any liner gloves you plan to wear. Also, sizing varies between brands, so always check the specific size chart rather than assuming XL is the same across the board.