Helmet laws are widespread.
In 28 countries, helmet use is mandatory — often for children, but some laws cover adults too. In the U.S., about 250 cities and states have their own requirements.

Tennessee Law: All bicycle operators under 16 years of age must wear a bicycle helmet on any highway, street, or sidewalk.

Mississippi Law: It is unlawful for any person under the age of eighteen (18) to operate or be a passenger on a bicycle, tricycle or skateboard on a public road, public bicycle path, or other public right-of-way unless at all times that person wears an approved helmet of good fit, fastened securely upon the head with the straps

Arkansas Law: 

Getting the Perfect Fit

A poorly fitted helmet won't protect you properly. Here's how to get it right:

Helmet should fit snugly without sliding around.

• It must sit level and low on your forehead — 1–2 finger widths above your eyebrows.
• Straps should form a “Y” under your ears and be snug.
• Only one finger should fit under the chin strap.
• You should barely see the helmet’s front rim when looking up.

Helmet Lifespan: When to Replace

Helmets wear out. Replace yours every 5–10 years — or immediately if:

• It’s been in a crash.
• You see cracks in the shell or liner.
• Straps are worn or broken.
• Pads or parts are missing.

Newer helmets often come with better technology too.

Avoid used helmets — they mold to the original owner’s head and may not fit or protect you properly.

Can a Bike Helmet Be Used for Other Sports?

Bike helmets are made for cycling crashes. Multisport helmets cover activities like skating and scootering too, but most bike helmets aren’t designed for all sports. (The CPSC has a full guide if you want to match the right helmet to the right sport.)