Fitting A Bike Helmet
Put the helmet on your head so it sits evenly between the ears and
rests low on your forehead – it should only be about 1-2 finger widths
above your eyebrow.
Put foam pads inside the helmet so it feels comfortable but really
snug. Usually, the helmet includes more than one size of foam pads
that can be velcroed inside the helmet for a better fit.

Tighten the chin strap as snugly as possible. Adjust the junction of
front and back straps just under the ears and secure back strap
without putting pressure on the front strap.
If all of this sounds confusing, follow the simple 5-Step Helmet Fit
Test at right.

A Good Helmet Fit is as important as wearing one...but it takes time. Allow as much as a half hour to get a proper helmet fit. If fitting your child, don't try to “rush” it as they are trying to go outside to ride. Do it while they're relaxed and you have plenty of time. Then secure the adjustments so the helmet is ready for the next ride.
Buying A Bike Helmet
Buy a helmet that has been tested and meets the uniform safety standard issued by the U.S. Consumer Product Safety Commission (CPSC), or one or more of the voluntary bicycle helmet standards like ASTM, Snell or ANSI. You can tell this by looking for a label or sticker that says the helmet meets the standard.
Select a brand and size that fits well prior to any adjustments. Adjustable sizing pads are often included to help ensure a better fit. Buy one that's comfortable and attractive. You”ll be more likely to wear it.
Buy a helmet that fits your child now, not a helmet to “grow into.”
Replace any helmet that has been involved in a crash!
FACT: A bicycle helmet reduces the risk of serious head and brain injury by 85-88%. But it's not enough to simply buy and wear one – you need to make sure it fits properly.