When people talk about suit adjustments, they are almost always talking about the jacket. The jacket is the most complex and structured part of a suit, and it is also the area where alterations are most limited. While tailoring can improve a finished jacket to a point, there are clear boundaries beyond which adjustments become ineffective or counterproductive.

The sport coat is often treated as a more casual alternative to a suit jacket, but when it comes to fit, the underlying principles are largely the same. As Brian Kreps explains, at B. Kreps we do not style the fit of a sport jacket any differently than a suit coat unless a client specifically requests it. In both cases, the objective is comfort, balance, and a silhouette that follows the natural lines of the body.

This question comes up frequently because sleeve length is one of the most visible indicators of whether a suit fits properly. It is also one of the easiest details to get wrong. While taste plays a role, there is a widely accepted guideline that produces a clean, confident result for the vast majority of wearers.