Pairing a sports coat and jeans can give anyone a dressy-but-still-casual look, but it's easy for the combination to go off the rails and look terrible. Luckily, with a little attention to fit and a good match between the style of your coat and jeans, anyone can create a winning pair.
Image from bobbivie
Balancing how formal your overall outfit will make the two items work together, too. The Art of Manliness explains:
The main reason the sports coat and jeans look fails is that the two pieces are too jarringly matched. Generally, the jeans are too casual, and the jacket is too formal. And often both pieces are too baggy. The solution of course is to make sure that top and bottom complement each other well -- that your jeans are a little more formal, your jacket is a little more casual, and everything fits well.Remember, fit is the foundation of style!
It's a simple rule to keep in mind if you're going for that casual sports coat look. Aim to dress the more formal item, the sports jacket, down by using the right accessories. For example, skipping the tie but still opting for a button down shirt will bring the jeans and jacket to a similar level and pull everything together. For some photo examples of sports jackets and jeans together, hit the link below.
How to Wear a Sports Jacket with Jeans [Art of Manliness]