Helmet size guide

A helmet that doesn't fit doesn't protect. Two centimetres too big and it shifts the first time you brake. Two centimetres too small and you'll stop wearing it within a week.

Here's how to find your size in five minutes, at home, with a tape measure.

1. Measure your head circumference

Use a soft sewing tape measure. Failing that, a piece of string that you then lay against a ruler.

• Place the tape about 2 cm above your eyebrows, roughly a finger and a half.
• Run it above your ears, then around the widest point at the back of your skull, the small occipital bump.
• Keep it snug without squeezing: the tape should hold on its own, not mark the skin.
• Measure three times and keep the largest value. Hair down, no bun.

In the vast majority of cases you'll get a figure between 52 and 64 cm.

2. The size chart

This is the standard European scale, the one published by Stormer for the Strike range and followed by almost every ECE-approved helmet we sell.

3. Between two sizes, go for the smaller one

The comfort padding in a new helmet compresses. Expect the equivalent of half a centimetre to a centimetre after about ten hours of wear.

A helmet that feels slightly tight at the first fitting will be perfect in two weeks. A helmet that feels comfortable from the first minute will be too big in a month.

The one exception: if the helmet causes a painful, localised pressure point on your forehead or temples as soon as you try it on, that's not a size problem but a head shape problem. Go up a size or change model.

4. The fit test, in four moves

1. The tilt. With the helmet fastened, grab it from the back and try to roll it forwards. It should stay in place.
2. The twist. Hold the helmet with both hands and turn it. Your skin should move with it. If the helmet turns without dragging the skin on your forehead, it's too big.
3. The cheeks. On a full-face helmet, the cheek pads should press lightly on your face, enough to change your voice a little. They will settle.
4. The chin strap. Once fastened, you should be able to slide two fingers between the strap and your throat, no more.

Keep the helmet on for ten minutes before deciding. Most wrong sizes show up at minute eight, not minute one.

5. Head shape: the factor nobody measures

Two heads with the same circumference don't have the same shape. There are three profiles: long oval, a head longer from front to back than it is wide, intermediate oval, the most common in Europe, and round oval.

If your helmet is the right size but presses on your forehead and the back of your head, your head is rounder than the helmet. If it presses on your temples, your head is longer.

Either way, changing size won't fix it, you need a different model. It's exactly the kind of thing that gets sorted in three minutes at the workshop and never online.

6. Which approval for which use

• EN 1078, the bicycle standard. Fine for a city scooter limited to 20 km/h and for short journeys.
• ECE 22.06, the motorcycle standard, far more demanding: rotational impact testing, trials at several speeds. It's the level of protection we recommend for daily use, and it's the approval carried by the Stormer and SHOT helmets in our catalogue.

Since 1 September 2026, helmets have been mandatory in Belgium for motorised personal vehicles able to exceed 20 km/h. Almost all the scooters we sell are affected.

→ Read the article on the new requirement

7. When to replace a helmet

• After any impact, even with no visible damage. The polystyrene liner crushes only once, it doesn't spring back.
• After five years of use, or seven years after the manufacturing date shown on the inside label. Padding and glues age.
• If the inner padding has compressed so much that the helmet moves. On some models only the padding needs replacing, just ask us.