How do I know if my BMX helmet fits correctly?

A properly fitting BMX helmet should sit level on your head, covering your forehead with about one inch of space above your eyebrows. It should feel snug all around without pressure points. With the chin strap fastened, you should not be able to push the helmet forward off your forehead, backward off the rear of your head, or side-to-side more than an inch. If the helmet rocks in any direction, it's either too large or the padding needs adjustment. With the chin strap undone, shake your head vigorously — the helmet should stay in place.