How to find your motorcycle helmet size
Choosing the right size of motorbike helmet is more important than it seems. All you need to do is measure the circumference of your head in centimetres and compare it with the size chart. But it’s not all about the number: each brand may size their helmets slightly differently, and the shape of the helmet’s interior also affects how well it fits your head. In this guide, we explain how to measure yourself correctly, how to interpret the sizes, and what you should bear in mind before choosing your helmet.
Measure your head
You’ll need a flexible tape measure (sewing tape measure). If you don’t have one, use a piece of string and then measure it with a ruler.
- Place the tape measure just above your eyebrows (about 1 cm above).
- Run it over your ears, going around the widest part of your head (the back of your head).
- Keep the tape horizontal, neither tilted up nor down.
- Tighten it just enough — without pulling the skin but without any slack.
- Note down the measurement in centimetres. That is your size.
Tip: Measure two or three times and go with the largest measurement. It’s better to have a helmet that’s slightly snug (it will mould to your head with use) than one that’s loose (it will never fit better).
Motorcycle helmet size chart
| Circumference (cm) | Size | Reference |
|---|---|---|
| 53-54 cm | XS | Small head |
| 55-56 cm | S | Small to medium head |
| 57-58 cm | M | Best-selling size |
| 59-60 cm | L | Large head |
| 61-62 cm | XL | Very large head |
| 63-64 cm | XXL | Extra large head |
Cómo saber si el casco te queda bien
Estas son las pruebas que debes hacerte.
- Prueba del movimiento: Agarra el casco por los laterales y muévelo arriba y abajo. La piel de tu frente debe moverse con el casco. Si el casco se desliza sobre la piel, es grande.
Prueba del dedo: Intenta meter un dedo entre tu sien y el acolchado. Si cabe con facilidad, necesitas una talla menos. - Prueba de presión: Llévalo puesto 5 minutos. Si notas puntos de presión en la frente o las sienes, puede ser pequeño o esa forma no es para tu cabeza. Un casco debe apretar uniformemente, sin puntos de dolor.
- Prueba de la correa: Abrocha la correa. Debe caber un dedo entre la correa y tu barbilla, pero no dos. Si te la puedes quitar sin desabrochar, está mal ajustada.
- Regla de oro: Un casco nuevo debe quedar ajustado tirando a prieto. El interior cede entre un 10-15% con el uso durante las primeras semanas. Si te queda cómodo de entrada, en un mes te quedará holgado. Esto aplica sobre todo a cascos de gama media y alta con interiores de espuma viscoelástica.
Types of helmet – does size matter?
Your head circumference is the same regardless of the helmet you choose, but the fit experience varies:
Full-face: Getting the size right matters most here. The helmet wraps around the entire head including the chin. If it’s too large, it will move when you turn your head and become uncomfortable on the road. If it’s too small, it will press against your forehead and temples.
Open-face (Jet): More forgiving with sizing as there’s no chin guard. But it’s still important that it doesn’t wobble — a loose jet can lift in the wind at speed.
Modular: Similar to a full-face. The flip-up chin guard doesn’t affect the size but does change the feel — with the chin guard open it may feel slightly looser.
Trail / Adventure: The interior tends to be more spacious to accommodate visors and ventilation. If you’re between two sizes, try both.
Choose your helmet
Frequently asked questions about helmet sizes
Does a motorbike helmet wear out with use?
Yes. The inner padding moulds to the shape of your head during the first 2–4 weeks of use. That’s why a new helmet should fit snugly, almost a little tight. If it fits perfectly on the first day, it will be too big for you in a month’s time. The shell (outer casing) doesn’t stretch — it’s the inside that changes.
What should I do if I'm between two sizes?
If your head measures exactly 58 cm (between M and L), choose the smaller size (M in this case). The interior will stretch to fit. If you choose the larger size, the helmet will end up wobbling. The exception: if, when trying on the smaller size, you feel pain or severe pressure at specific points (not just general tightness), try the larger size — it may be that the shape of the helmet doesn’t suit your head.
Can I buy online without trying the helmet on?
Yes. Measure your head using the guide above and choose your size from the size chart. If it doesn’t fit, at The Urban Rider size exchanges are free of charge — we’ll send you the new size and you can return the one that doesn’t fit. No cost and no hassle. Over half of our online customers get it right first time using the size chart.
Is the size the same for men and women?
Yes. Helmet sizes are unisex — they are based on head circumference in centimetres, regardless of gender. A 57 cm size is a M for both men and women. What can vary, however, is the shape: smaller heads (XS–S) are more common among women, and some models in those sizes have specially adapted linings.
How often should you replace your motorbike helmet?
We recommend replacing your helmet every 5 years from the date of manufacture (not the date of purchase). The impact-absorbing polystyrene (EPS) degrades over time due to temperature and sweat. If the helmet has suffered a heavy blow — even if there is no visible external damage — it must be replaced. The EPS becomes deformed internally and loses its shock-absorbing capacity.
