What is the size of a motorcycle helmet?

[MelanieLee]

Motorcycle helmet sizes are L size 58-62cm, M size 55-58cm, and S size 51-55cm. Below are the specific details for helmet selection: Helmet requirements: The helmet must have impact-absorbing padding inside, and the weight of the helmet should not exceed 2KG. The helmet should not be stuffy or obstruct breathing, should provide a wide and clear field of vision without obstruction, and the static field of vision angle should be no less than 105 degrees. Helmet size: Pay attention to the helmet's ventilation and size. When wearing the helmet while riding, it should not feel tight around the neck or tightly wrap the head, causing difficulty in breathing. At the same time, the helmet size should be chosen such that shaking the head does not move the helmet, and frequent removal and wearing do not excessively wear out the helmet's bottom edge protective cover. It is recommended to choose a helmet that is 1~2cm larger than the head circumference.

[StSabrina]

I've been riding motorcycles for several years, and helmet sizing is something you really need to pay attention to. The standard size range is from XS to XXL, typically covering head circumferences from 52cm to 64cm. Every time I choose a helmet, I personally measure my head by wrapping a soft tape measure around the area just above my eyebrows, making sure it's neither too tight nor too loose. The helmet must fit snugly: if it's too large, it will wobble, increasing the risk of accidents; if it's too small, it will press on the temples, making long rides extremely uncomfortable. I've tried multiple brands like Shoei and AGV, and their size charts can vary—for example, size S is often 55-56cm, and size M is 57-58cm. I recommend going to a physical store to try on helmets for about half an hour, checking that your cheeks are lightly pressed but you can still turn your head. Safety comes first; an ill-fitting helmet compromises protection and makes riding feel unsafe.

[Moore]

In my daily routine of helping customers choose helmets, I find that size selection is crucial, typically based on head circumference in centimeters: S is 55-56, M is 57-58, L is 59-60, and so on. I always have them measure the widest part of their forehead with a soft tape measure, ensuring the tape is flat and not too tight. A properly fitted helmet should feel comfortable and not shift around; slight pressure on the cheeks when new is normal. There are noticeable differences between brands—for example, Arai suits flatter head shapes, while HJC is designed for rounder heads. After measuring, I recommend trying on a few, as size discrepancies are common, and both too loose or too tight should be avoided. A well-fitted helmet enhances the riding experience and reduces fatigue.

[Eloise]

Motorcycle helmet size directly impacts safety, and I emphasize this point. A helmet that's too large can easily come off during a crash, leading to severe injuries, while one that's too small causes pain and distracts the rider. Standard sizes are categorized by head circumference, starting from around 50 cm. To measure, use a soft tape to wrap around your head once, and when trying on, ensure the helmet is stable without wobbling. An ill-fitting helmet reduces protection, so check standard guidelines but verify personally. Choosing the right size ensures both comfort and protection.