There’s nothing better than the freedom that comes with getting out on two wheels. Whether you’re biking on the road, on the trails, or exploring your city, the most important piece of gear you have (besides your bike) is your helmet. It’s important to know how to measure yourself for a bike helmet and it’s the first step to finding the right helmet for you.

Finding Your Helmet Size

What You’ll Need

• A flexible measuring tape OR
• A piece of string/ribbon and a ruler

How Do You Determine Your Helmet Size?  

Measure your head circumference in centimeters by wrapping a flexible tape measure around the largest portion of your head—about one inch above your eyebrows. If you don’t have a flexible tape measure you can also use a piece of string and then measure the length of the string after with a ruler.

• Youth S: 48-52 CM
• Adult XS: 48-52 CM
• Adult S: 51-55 CM
• Adult M: 55-59 CM
• Adult L: 59-62 CM
• Adult XL: 61-65 CM

What if you’re in between sizes? If you’re in between two sizes we recommend heading to your local Smith retailer so you can try on the sizes in person and find the perfect fit. 

Final adjustments: Once you’ve determined your size and ordered your new bike helmet, there are a couple of final adjustments to make so that it fits you properly. Use the adjustment dial at the back of the helmet to fine-tune the fit of your helmet. Your helmet should feel snug but not tight and should stay put if you shake your head up and down and back and forth. Next, buckle the chin strap, and adjust it so that if you open your mouth wide, your helmet presses slightly into the top of your head.  You should be able to fit two fingers between the buckled helmet chin strap and your chin. 

A helmet is by far one of the most important pieces in your bike kit and now you know how to properly measure yourself for a bike helmet. If you have any other questions we can answer, don’t hesitate to ask.