How do I know the size of my motorcycle helmet?

The match between the size of the motorcycle helmet and the head is a key factor in ensuring the safety and survival of the rider in an accident. Many novice motorcyclists neglect this important detail and often opt for a larger helmet to reduce the feeling of being locked up. However, it should be noted that 4% of motorcycle accident deaths were still wearing helmets!

An alarming figure that underlines the importance of the conditions of use of the helmet. On the one hand, it must be of good quality and must perfectly match the size of the head. On the other hand, it must always be attached.

In this mini guide, we will know how to choose your motorcycle helmet size.

Executive Summary

1- Why buy your helmet at your size?

2- Which size should I choose for my motorcycle helmet?

3-Practical advice before choosing a motorcycle helmet size

1-Why buy your helmet at your size?

In principle, whether integral, modular or Jet, a helmet is always worn to protect the head from accidental trauma. It is the most important safety device that a motorcyclist must be aware of. Wearing the wrong size helmet may have major consequences on the motorcyclist’s safety. A helmet that is too wide for the circumference of the head may be expelled in an accident and not provide the necessary protection.

On the other hand, a helmet that is too tight can be uncomfortable and embarrassing when driving. Therefore, to ensure both safety and driving comfort, it is imperative that the helmet is precisely adapted to the morphology of the head. Thus, a good helmet should not be too big or too tight.

2- Which size to choose for your


The first step in choosing the right motorcycle helmet with the right size is to measure the head circumference with a tape measure. You can easily do this by measuring the circumference of the head from a point halfway up the forehead while running through the back of the head (the occiput). For more accuracy, it is better to repeat the measurements at least 3 times. Then compare the number you will get in the standard size grid to determine your motorcycle helmet size, as in the example below:

Head circumference in cm Helmet size
51-52 XXS
53 – 54 XS
55 – 56 S
57 -58 M
59 -60 L
61 – 62 XL
63 – 64 2XL
65 – 66 3XL
67 – 68 4XL
69 – 70 5XL

The grids differ slightly from one manufacturer to another, but in general it is a clue that will at least help you to pre-select the right helmet to choose.

In any case, it is always advisable to try the helmet before completing the purchase, especially if you are wearing glasses. A test will allow you to check if the helmet is of the right size but also if it can be worn with the type of glasses you have.

You know it’s the right size helmet when:

  • You feel no pain when you wear it, especially in the forehead.
  • The helmet is not so comfortable, and you feel it slightly tight. Don’t worry, it’s quite normal because the protective foams will pile up to adapt to the morphology of your head.
  • The helmet ensures a correct fit when the tether strap is closed, it does not interfere with head movements and does not extend to the forehead.
  • No part of the helmet is an obstacle in your field of vision.
  • You feel a slight pressure of the protective foams on the top of your head and cheeks, ensuring that there is no free space between the head and the inner part of the helmet.

3- Practical advice before choosing a motorcycle helmet size

  • Never wear a worn helmet, or borrow one from another person. The inner foams of the helmet end up taking exactly the same morphology from the head of the first user. So, even if you find it comfortable, be sure it will be less effective in a shock.
  • Replace your helmet immediately after an impact.
  • Excessive use of the headset may reduce its effectiveness and initial life. In this case the protective foams will pile up, which will widen the inner part of the helmet. This may also change the correct size of the motorcycle helmet and reduce the level of protection.