Lee Cooper Shirt with Paisley Print

This style is a regular fit, so it is designed to sit slightly relaxed, not tight. In most Lee Cooper shirts, Medium usually fits chest range around 38–40 inches, depending on the exact cut and fabric. If your usual size is Medium in shirts, then this item should generally fit you comfortably in Medium. So yes — it might fit a Medium size, especially if you prefer a normal/regular fit rather than a slim fit. If you like a slightly looser look, Medium is a safe choice; if you prefer a more fitted look, you could consider Small.