Choose a hat that is right for your head size. You can measure your head circumference by wrapping a measuring tape around your head so that it runs across the middle of your forehead and just above your ears (not across your ears). Much like shoe size, the circumference is unique to a person and does not change for adults. You can measure your child’s head circumference the same way or check it from your child’s medical records.

If you want a tight cap, choose the size closest to your head circumference. If the size falls between the cap sizes, choose a larger cap size. If you want to have a looser fit, you can choose a size one or two sizes larger.