If you're buying one t-shirt for daily wear, regular fit is the safer bet. It's more versatile, layers cleanly under a jacket, and flatters most body types. Oversized fit is a style choice—it looks great if you're going for a relaxed, streetwear vibe, but it can feel sloppy if not intentional. Think about your week: if you're mostly at a desk, running errands, or grabbing coffee, regular fit adapts. If you live in a creative studio or your weekends are all about lounging, oversized might be your default. Below, we tear down the common advice, rebuild a simpler default, and stress-test it so you can choose with confidence.