Should I buy an M or L size helmet for a head circumference of 58cm?
3 Answers
A head circumference of 58cm should buy an L size helmet. Introduction to motorcycle helmets: A motorcycle helmet is a head protection device designed for motorcycle riders and passengers. Its primary purpose is to protect the rider's head during impacts, preventing or reducing injuries and potentially saving the rider's life. Correct way to wear a helmet: When wearing a motorcycle helmet, the helmet should be parallel to the head, with the helmet's edge positioned about 1cm above the eyebrows. There should be about two fingers' width of space at the strap under the chin. After properly wearing the helmet, there should be no side-to-side movement.
My head circumference is also around 58cm. When I bought a helmet before, I chose a size M which turned out to be extremely uncomfortable—it pressed on my temples and caused pain. Later, I switched to a size L and it felt much better, even allowing room for a cheek pad. Helmet sizing varies significantly between brands. For instance, 58cm might be the upper limit for size M in some brands, while in others it's the starting point for size L. You really need to try them on to check the fit. From a safety perspective, a helmet should fit snugly without causing headaches, and there shouldn’t be much movement—otherwise, it could shift during a crash and fail to protect your head. I’d recommend visiting a physical store to try on several brands. Based on my experience, it’s better to go slightly larger than smaller, as you can always adjust with additional padding over time. Never blindly order online just for convenience—the sizing charts are only a rough guide. Everyone’s head shape is different, and factors like forehead width can also affect the fit.
I often help friends choose riding gear, and selecting a helmet for a 58cm head circumference requires special attention. In standard sizes, M typically fits 56-57cm, while L fits 58-59cm, putting you right at the threshold. My recommendation is to prioritize the L size, as it offers more flexibility with liner thickness and accommodates slight head expansion from summer sweating. The key to a proper helmet fit is zero movement when worn but without pressure points; measure your head circumference three times and average the results for better accuracy than relying on a single measurement. Sizing varies significantly between brands—AGV tends to run half-size smaller, HJC often half-size larger—so always check the manual or online reviews before purchasing. Safety first: an oversized helmet can be adjusted with thicker liners, but one that's too small is problematic. During fitting, test stability by shaking your head—never rush and overlook these critical details.
