Arai Size Chart and Fitting Guide

Sizing information is provided by the manufacturer and does not guarantee a perfect fit. Our expert staff would be happy to assist if you need help finding your size - contact us.

Head Circumference

(measurements in centimeters)
49 - 50 51 - 52 53 - 54 55 - 56 57 - 58 59 - 60 61 - 62 63 - 64 65 - 66

To measure the circumference of your head wrap a cloth measuring tape around your head just above your eyebrows. Pull the tape comfortably snug, and read the length. Compare it to the measurements in the Head Circumference table and then check the Size Selection table to ensure the helmet series you are interested in fits your head shape.

Size Selection

Quantum Series Round Oval
Astral Series Round Oval
Profile Series Long Oval
Signet Series Long Oval
RX-7 Series Intermediate Oval
Vector Series Intermediate Oval
Classic Series Intermediate Oval
SZ/m Series Intermediate Oval
SZ/RAM Series Intermediate Oval
VX-Pro Series Intermediate Oval
XD Series Intermediate Oval

Determining Head Shape

After many, many years of listening to riders, Arai has found that helmet satisfaction starts with understanding helmets. Most importantly, understanding how proper fit affects helmet performance during everyday riding, and how that comfort extends to the helmet's interior shape. This is why Arai has gone to the considerable effort to design, create, and offer three different interior shapes. (Arai does not believe that all-day comfort can be achieved by trying to stuff every different head shape into a single helmet interior shape.)

In order to offer the most comfort, a helmet interior must fit snugly around the entire head contour. (This is partly determined by firm, even pressure at all contact points, and without pressure points that could become uncomfortable in the future). A previous helmet of the same brand, model and size - even if an Arai - may not offer the same fit as a current model or size because the evolution of design and use of new materials can affect the final design and shape (For example, such advances and refinements have made the interior shapes of our new RX-7 Corsair and Quantum-2 models able to fit more riders than their immediate predecessors, the RX-7 RR4 and Quantum/f.).

Attention must also be paid to the fit of the model's shape around the crown of your head - and not with facial fit. (The part that is contacted by a baseball cap's band, for example, is the crown). Cheek pads in all Arai helmets can be replaced with a size that better suits your facial structure, so the possible need for different cheek pads should only be addressed after the crown is properly sized. All too often, tight OEM cheek pads will result in purchasing a helmet one or even two sizes too big - in effect sizing the face and not the head! The end result will be a loose and noisy helmet, as described above. Riders with a strong jaw or heavy cheeks should first remove the cheekpads completely in order to not be distracted in determining crown fit.

How can you determine which of Arai's three interior shapes is best suited for you? In general, Arai interiors for the North American markets have an oval shape orientation (somewhat longer front-to-back and a little narrow from side- to-side) because that is the shape that tends to fit most. Different models then vary slightly based on that general Oval shape to accommodate a much wider fit range.

    Very long front-to-back, very narrow side-to-side. On this end of the scale, we have the new Profile model, offering additional forehead room for those who find that most helmets have pressure points in the forehead.
    A little shorter front-to-back and a little wider side-to-side than the Long Oval. This next fit package comes in the RX-7 Corsair model, which begins the shift from oblong towards round.
    Even a little shorter front-to-back and a little widerside-to-side. This next fit package is represented by both the Quantum-2 and our Astral-X models.

The Astral-X has a slightly more "relaxed" fit - a bit more room in the forehead area - mainly because the Astral has a non-removable liner.

The Quantum-2's liner, on the other hand, is fully-removable, which makes it feel a bit more "round". Be sure to try both on to determine which feels better on your head.

No one pays more attention to the subtle variations and the infinite possibilities of the human head shape than Arai. And even though they know they can never build a perfect shape for everyone, Arai spends the extra time and expense to make a genuine effort to offer shapes that allow more people to find a better and more comfortable fit than by simply offering one shape in every model.

This is why it's important for you to understand the different aspects of sizing as it relates to brands, models and in Arai's case - interior shapes.