Shopping for a new helmet? It's important to consider your head shape along with your head circumference. Head shape is often the most challenging factor in finding the correct (and most comfortable!) fit. Helmet size charts will indicate the circumference of a given helmet/size. While this can certainly help point you in the right direction, it is recommended that you try a helmet on in person to ensure a correct fit.
Head shape can differ, with some being more oval (longer from front to back) or round (similar width and length). Most helmet models will cater to either oval or round shapes, but many also fall somewhere in between. Even if you have a rounder shaped head, you may still fit in an oval shaped helmet or vice versa.
Oval Fit
While liners and padding determine the more precise fit of a helmet, the overall shape is based on the helmet shell.
Helmets with an oval shell have a greater distance from front to back when compared to a rounder helmet. You may need an oval fit helmet if you find you experience pinching at the front or back of a helmet and/or gapping at the sides.
Round Fit
A round fit helmet will have more fit allowance on either side. You may need a round fit helmet if you find you experience gapping at the front or back of a helmet and/or pinching at the sides.
Trial and Error
Buying a helmet that fits correctly is a lot like trying to buy a pair of jeans without stretch; even within the same brand, the same size across multiple styles might fit you differently! Achieving the best fit often requires some trial and error. The most effective approach is to try on several styles, shapes, and sizes until you find the one that suits you best. Additionally, consulting with a helmet fitter at a tack shop is invaluable in ensuring you select the best option for your needs.