Fit is snug on my big head but not at all uncomfortable. It will also stretch over time. I know this because it's replacing one I bought and used for over 2 years. I love the cap. Keeps the sweat out of my eyes, is cool, and protects my head from sunburn in the summer. I bring it with me on most rides, including cold ones where I start off with a heavier cap. If you want a light weight cap that fits nicely under a helmet, it's hard to go wrong with this choice.