Customers often get sizings wrong for their motorcycle gloves. What you are going to be using the gloves for naturally influences how they should fit. For those who are thinking of getting a pair of motorcycle gloves for a present or if they simply haven’t bought a set before you can use this size chart here for a broad idea.
Summer gloves need to be snug without being restrictive. The wrist stitching should be on comfortably on your wrist, not on your hand and the fingers should not be pushing against the ends. The wrist cuffs do vary wildly from long or short on summer gloves depending on it’s design. You should think about whether you want the cuff over the sleeve of your motorcycle jacket, or tucked inside instead.
Winter gloves are different and should be treated as such. They should not be as snug as summer gloves (but not loose) for the key reason of insulation. Winter gloves work by trapping a layer of air in your glove which your hand warms up. If the glove is too snug then this thermal layer cannot work and after 5 minutes of riding your previously warm hands just end up cold again. They ideally need to be waterproof if being used in the UK, wet and cold hands are a dangerous combination!
For information all the gloves above are the same fit size Medium and are the Spada Predator long cuff summer gloves on the left, Buffalo 322 summer short cuff gloves center and Buffalo Arctic Winter gloves on the right. Note how different they look despite fitting the same hand size!