The biggest difference between a blazer and a suit jacket is that a blazer is a stand-alone garment, while a suit jacket always comes with matching pants. Another key difference is that blazers almost always feature one solid color, while suit jackets may use patterned fabric.

There are a few key main differences between a blazer and a suit jacket, the most important being that a suit jacket always comes with matching trousers made from the same fabric and with the same pattern. A suit jacket is made to fit slimmer than a blazer, and you shouldn’t layer a ton of clothing underneath it, save for a button down shirt.

A blazer is just a bit more casual than a suit jacket but is a level above a sport coat. Primarily, it’s the material that makes blazers more formal than sport coats. While the latter usually feature patterned fabrics, blazers are usually made of the same fabrics as the suit.