How to measure head for helmet

Learning how to measure helmet size takes only a few minutes. All you need is a flexible measuring tape, although string and a ruler work just as well.

Start by placing the measuring tape just above your eyebrows. Wrap it around the widest part of the back of your head, making sure it follows the full circumference.

The tape should sit comfortably against your head without pressing into your skin.

If you don't have a flexible tape, use a piece of string instead. Mark where the string meets, lay it flat, and measure its length with a ruler.

A common mistake when learning how to measure your head for a helmet is allowing the tape to tilt upward or downward.

Use a mirror or ask someone to help you keep it level. The tape should follow the widest part of your head, rather than sitting too high on your forehead or too low at the back.

Repeat the measurement two or three times to confirm your result. This is particularly useful if you're close to the boundary between two helmet sizes.

Once you know how to measure your head for a bike helmet, the next step is comparing your measurement with the manufacturer's size chart.

Helmet sizing can vary between brands and models, so don't rely only on labels such as Small, Medium, or Large.

Centimeter values are rounded equivalents. For the latest measurements and sizing instructions, refer to the individual product page.

Check the size chart for your helmet model: AURA Mips or NEON.

Head circumference is the starting point, but head shape also affects how a helmet fits.

An oval head is generally longer from front to back and narrower from side to side. A round head has more similar front-to-back and side-to-side dimensions.

Two people with the same head circumference may find that the same helmet fits differently because of their head shapes.

If you're unsure which shape best describes your head, trying on the helmet can help you identify pressure points and assess its overall fit.

The AURA and NEON product pages previously reviewed advised choosing Medium when between sizes. However, it's important to check the latest instructions for your particular model and measurement rather than applying a general sizing-up rule.

A helmet that's too large may move excessively, even when the retention system is tightened. A helmet that's too small may create uncomfortable pressure points or fail to sit correctly.

If you're between sizes, use the model-specific chart as your starting point and try the helmet on whenever possible.

A properly fitted helmet should feel secure without being uncomfortably tight.

Pay attention to pressure around your forehead, temples, and the sides of your head. These may indicate that the size or shape isn't suitable.

Then gently move your head from side to side and forward and backward. The helmet should remain in position without excessive movement.

If the helmet feels unstable or uncomfortable despite adjustment, consider another size or model.

Measuring your head helps you choose a starting size, but the final fit check is just as important.

Your bike helmet should sit level on your head, with the front edge just above your eyebrows rather than tilted backward.

Adjust the rear retention system until the helmet feels comfortably secure. The system should help stabilize the helmet without creating excessive pressure.

Next, check the straps:

• The side straps should form a V around each ear.

• The chin strap should fit snugly beneath your chin.

• The helmet should stay in position when you gently move your head.

If your helmet includes a Mips system, some movement between its internal components may be part of its design. This is different from the entire helmet fitting loosely on your head.

Learn more in our guide to what a Mips bike helmet is.

Your hairstyle and accessories can influence helmet fit.

Bulky hairstyles, hair positioned beneath the retention system, or certain glasses may change how comfortably the helmet sits.

If you wear glasses, check that the frames don't interfere with the straps or create pressure points around your temples.

For practical hairstyle advice, read our guide to preventing helmet hair without compromising your fit.

In colder weather, use only helmet-compatible caps or liners and recheck the fit with the layer in place. Avoid automatically sizing up to accommodate a bulky hat.