Free tools for choosing and riding with the right gear. No sign-up, nothing to install, and they work on your phone.
Motorcycle helmet size calculator
Enter your head circumference in centimetres or inches and get your size for HJC, Bell, Shoei, Arai and Scorpion helmets at once, with how to measure and how a helmet should fit.
Helmet law lookup by state
Pick your state to see whether every rider must wear a helmet, which riders the law covers, and how many riders died there without one in 2024.
Sena intercom comparison chart
Every Sena intercom side by side, from the 60X and 60S EVO down to the 10S and 5R: mesh, range, talk time, price and which models work together.
Cardo intercom comparison chart
Cardo Packtalk Pro, Edge and Neo, Freecom 4X and Spirit HD compared on price, mesh, range, talk time and features.
Which tool do you need?
- Buying a helmet online? Start with the size calculator. Sizes differ between brands, so a medium in one can be a small in another. Measure your head, then check the brand chart before you order.
- Riding in another state? Use the helmet law lookup to see whether riders and passengers there must wear a helmet. Laws change, so check the state’s official source before a long trip.
- Choosing an intercom? Use the Sena and Cardo charts to compare models within a brand, then read Cardo vs Sena to choose between them. If your riding group already uses one brand, match it.
How we build these tools
The size calculator uses each manufacturer’s published size chart. The helmet law lookup combines state helmet laws with fatality data from the US National Highway Traffic Safety Administration. The intercom charts use manufacturer specifications. We update them when brands release new models or change their charts. Read how we research for more on our sources.
More from Throttle Buff
- Research and data: our motorcycle safety studies, with state-by-state tables you can cite.
- Best motorcycle helmets and best motorcycle intercoms: our main buying guides.