icon How to measure the size of a bicycle helmet?

How to measure the size of a bicycle helmet?

Although it is not mandatory for adults, wearing a helmet is essential to guarantee the safety of the cyclist on the bike. One of the decisive criteria for ensuring comfort and a good level of protection is the size of the bicycle helmet.

But how do you know your size and measure your bike helmet? Here are our tips.

What are the different sizes of bicycle helmets?

There is a very wide range of bicycle helmets on the market, for adults and for children. These products come in a huge range of different designs and sizes.

Most bicycle helmets are offered in 2 to 4 sizes, ranging from size S to size L :

  • Size S for a head circumference between 54 and 57 centimeters
  • Size M for a head circumference between 57 and 59 centimeters
  • Size L for a head circumference between 59 and 62 centimeters

Some brands, such asthe CGM brand , offer bicycle helmets in size 3XS (50 cm), XL (60cm) or even XXL (61 cm).
Order your CGM helmet .

Other brands offer one-size-fits-all collections , with helmets featuring an adjustable dial to adjust the helmet closer to the contours of the head. Discover the brand new Cosmo Connected Premium helmet in one size.

Sometimes two sizes of bicycle helmets are offered:

  • S/M: for a head circumference between 54 and 59 centimeters
  • L/XL: for a head circumference ranging from 59 to 62 centimeters

Keep in mind that the size guide will not always be the same from one brand to another. The size that suits you may therefore be different depending on the model.

For children, there are generally two sizes of bicycle helmets: bicycle helmets for ages 4 to 10 and bicycle helmets for children under 5. Some models are also suitable for children from 9 months (this generally corresponds to a head circumference of 45 cm).

Are you looking for a child's bicycle helmet? Discover the models of bicycle helmets for babies and children offered by Max And The City.

→ Warning : for children under 12, wearing a helmet is mandatory. Consult our article on the subject to learn more about the obligation to wear a bicycle helmet.

How to know your bike helmet size?

Choosing a bicycle helmet adapted to your morphology is essential for several reasons.

This allows, first of all, to guarantee the safety of the cyclist. Indeed, a helmet that is too wide, which moves on the head, will not effectively absorb shocks in the event of a fall. In addition, choosing the right size helmet is essential to ensure optimal comfort when cycling . Indeed, a helmet that is too small will exert an unpleasant pressure on the head, which can generate inconvenience and musculoskeletal pain in the neck.

How to measure your head circumference?

In order to know the size of your bicycle helmet, you will have to start by measuring the circumference of your head.

To do this, take a tape measure (or flexible seamstress tape measure). If you don't have one, use a string, shoelace or cable and a ruler (to measure the length of the string).

Then place the meter around the skull, horizontally. The measuring tool should be positioned above the ears and in the middle of the forehead, just above the eyebrows (about 20 mm above) and at the level of the occipital bump (this is the convex area located at the back of the skull). Be careful not to over-tighten or over-loosen the tape measure to ensure an accurate measurement.

Then take the measurement on the meter: this is the size you should use when choosing your bike helmet.

For the helmet to be perfectly adjusted to your head and to ensure optimal support, consider tightening the chin strap and adjusting the micrometric adjustment wheel at the back of the helmet shell, if the latter is fitted with one. Also note that some models of helmets come with removable and washable inner foam, providing additional padding so that the helmet completely hugs the contours of the head.

How do I know if my helmet is the right size?

Also, to check that the helmet is the right size , test its fit by shaking your head up and down and side to side; if the helmet moves, it is too big. Likewise, if you feel any pressure on the head (especially in the forehead, temples and jaw when closing the strap), it means that the helmet is too small. It will then be necessary to opt for the size above.

In addition to the size of the helmet, remember to take into account other criteria when choosing your helmet, such as the ventilation system (the number of vents present on the outer shell); the weight ; and the type of helmet (MTB helmet; BMX helmet; road bike helmet; city bike helmet, etc.).

To find out more on the subject, see our article: “ How to choose the right bike helmet? All our tips »

How to measure the size of a bicycle helmet?

After measuring your head circumference, all you have to do is refer to the brand's size guide to choose the appropriate size. At Max And The City, we provide you with a size correspondence table on each of our product sheets.

Discover all of our helmets

→ Good to know : if you hesitate between two sizes or if the measurement of your head circumference is between two sizes, it is then recommended to seek advice via our online chat.