Embodiments are disclosed for headwear including a crown and a size-adjusting mechanism extending around at least a portion of a perimeter of the crown. An example size-adjusting mechanism is adapted to selectively adjust a size of the crown, and includes an outwardly-protruding dial having a gear disposed in an interior of the dial, and a first and second band section each coupled to the crown. The gear of the example size-adjusting mechanism is configured to engage each of the first and second band section to adjust a relative position of the first and second band section relative to one another.