For a fitted look, choose your exact measurement. The hat should sit comfortably without being too tight.

For a relaxed fit, go one size up. This works well for casual styles and allows room for thicker hair.

If you're between sizes, consider the hat style. Structured hats fit better when snug, while soft hats can be worn looser.

Remember that some materials like wool may shrink slightly, while others like cotton may stretch over time.