There’s more to well-fitting jacket sleeves than the right length. Jacket sleeve width is an oft-forgotten aspect of fit, and a well-fitting sleeve subtly makes a jacket much more flattering. Compare Sean Connery’s James Bond to Jack Lord’s Felix Leiter. Whose sleeves look better? Connery’s sleeves neatly taper whilst Lord’s sleeves are very full from shoulder to cuff. Sleeves should taper to the cuff, and altering sleeve width can be a risky endeavour. The sleeve opening should be large enough to fit a double cuff with enough room for it to slide through easily. A sleeve that’s too tight is restricting and will crease readily. The sleeve’s width should also be in balance with other parts of the suit. A very tapered sleeve looks out of place on a suit with a full-cut jacket and wide trouser legs, but that doesn’t mean the sleeve should be as wide as the trousers legs are either. Connery’s sleeves mimic the taper of his trouser legs whilst Lord’s wide sleeves don’t mesh well with the rest of his outfit.
Sleeve length is the easiest part of the sleeve to alter—as long as buttonholes haven’t been cut—so there’s no excuse for sleeves that are too long. The jacket sleeves should end roughly at the wrist bone so they show 1/4- to 1/2-inch of shirt cuff when the arms are relaxed, and this applies to button cuffs and double cuffs. Showing shirt cuff is ultimately a personal preference, but it’s something James Bond does more often than not. Visually, it balances the shirt collar showing in above the back of the jacket collar. Practically, it protects the edges of the jacket sleeves and prevents fraying. Shirt cuffs and shirts are much cheaper to replace than an entire suit because of frayed jacket cuff edges.
Another thing related to the sleeve that people often mention is the armhole and that it should be high. A high armhole means that the armhole is short in height and the bottom of the armhole is high into the armpit. The armhole should be felt in the armpit, but it shouldn’t dig into the armpit. A higher armhole gives the arms more vertical motion, so even though it might feel tighter it is actually less constricting. The width of the armhole is also important, since an armhole that is too narrow will constrict movement and cause the upper sleeve to bind. The armhole cannot be altered, and most ready-to-wear suits have rather large armholes that can fit people of different shapes. Unfortunately that leaves the majority of men with an armhole that is often far too large.