How do I know if a helmet is too small or the wrong shape?

Pain spread evenly all around your head usually means the helmet is too small, so try the next size up. A single hot spot on the forehead or at the temples usually points to a shape mismatch, so try a different interior shape rather than a bigger size.

How long should I wear a new helmet before riding?

Wear it indoors for 15 to 30 minutes (NHTSA suggests 30 to 45) before riding or removing tags, and check for pressure points.

What is the most common head shape?

Intermediate oval: slightly longer front to back than side to side. Most helmets sold in North America follow it.

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Motorcycle Helmet Sizing by Head Shape

Two things decide whether a helmet fits: the size of your head and its shape. Size is a tape-measure number. Shape is whether your head is round, a bit longer than wide, or clearly longer than wide. A helmet in the right size but the wrong shape can still hurt, so here's how to get both right.

Step 1: Measure your head

Use a soft tape (or print our free tape measure). Keep it level, about 1 in / 2.5 cm above your eyebrows, and around the widest part at the back of your head. Snug, not tight. Measure twice and use the larger number [1][2]. Shoei describes the same line: 2 cm above the eyebrows, 2 cm above where your ears meet your head, and the most protruding point at the back [3].

Step 2: Find your head shape

Most riders fall into one of three shapes, and intermediate oval is the most common [4]:

Round oval: about as wide as it is long. Round heads tend to feel hot spots at the temples in oval helmets [5].
Intermediate oval: a little longer front to back than side to side. Most helmets sold in North America follow it [5].
Long oval: clearly longer than it is wide. Long-oval heads tend to feel hot spots on the forehead in rounder helmets [5].

Simple ways to tell: have someone take a photo looking straight down at the top of your head, with your hair flattened as much as possible [6]. Or think about helmets you've worn: pressure across the forehead means a helmet was too round for you, and pressure on the sides means it was too oval [4]. If you still can't tell, start with intermediate oval. Save your shape in your profile and we'll show a shape match note on every helmet deal.

Step 3: Use the brand's own chart

Charts differ by brand and sometimes by model. For example, Schuberth's Small is 54-55 cm [7], while Small is 55-56 cm on AGV's chart [8] and the Nexx chart [9]. So don't assume your usual letter size carries over. Brands also disagree about what to do between sizes:

Brand	If you're between sizes
Shoei	Try the smaller size first [3]
Shark	Usually the smaller size, since the foam compresses [10]
6D	Try the smaller one first [11]
HJC	Try the larger first, then the smaller [12]
Fox Racing	Size up [13]

That's why we size each helmet against its own brand's chart where we have it, and say so when we don't.

Step 4: The indoor wear test

Before you ride in a new helmet or take the tags off, wear it at home for 15 to 30 minutes. Sit, read, watch TV [6]. NHTSA suggests 30 to 45 minutes, because hot spots may not show up right away [4]. Stay off the bike: RevZilla notes it can't take a helmet back once it's been ridden in [6].

A new helmet should feel a little tight, with even pressure around your head [4] and your cheeks pushed up a little [6]. Liners break in: RevZilla says most give 15 to 20 percent over the first 15 to 20 hours of riding [6]. So snug is fine. Pain isn't.

All-over pain or one hot spot?

Where it hurts tells you what to change:

Pain spread evenly all around your head: the shell and liner are too small. Go up one size [14].
One hot spot on the forehead: the helmet is too round for your head. Look for an intermediate or long oval [4][14].
One hot spot at the temples or sides: the helmet is too narrow (too oval) for you. Look for a rounder shape [4][14].

Don't size up to fix a single hot spot. A bigger helmet that still presses in one place will be loose everywhere else, and a gap between your head and the liner works against you in a crash [14][6].

One rider's example

One rider measured into a Large on the Alpinestars Supertech M10 chart (Large is 59-60 cm, XL is 61-62 cm on the manufacturer chart [15]). After about 15 minutes indoors watching TV, the Large was painful all over, with no single pressure point. The rider exchanged it for the XL, which was never painful. It felt a bit snug out of the box, then broke in with even pressure all around and no hot spots. In the rider's words, it fits like a glove.

Because the pain was even all around, this was a size issue, not a shape mismatch. The M10 is listed as intermediate oval [15]. This is one rider's experience, not a rule about the M10 or Alpinestars. The takeaway is the general one above: a new helmet should feel snug and will break in, but if your chart size hurts evenly all around during the indoor test, try the next size up.

Rider fit ratings

As riders send in Fit Reports, we add fit ratings for specific models, for example "Some riders size up" with the count. A report counts only if the rider used a tape measure, said which size they wore and wore it for at least 15 minutes. Photo estimates of head size don't count. Models with fewer than five qualifying reports show nothing. Individual measurements are never shown. How fit ratings work.

Brand head-shape chart

Shapes come from the brand where it states them. Otherwise they come from RevZilla's product listings, which give an interior shape for each helmet, or from a distributor's chart. Each row links to its source. A dash means we found no source, so we don't guess. Checked October 18, 2026.

Brand	Model	Interior shape	Source
Arai	Signet-X	Long oval	Brand [16]
Arai	Quantum-X	Round oval	Brand [16]
Arai	Corsair-X, Contour-X, Regent-X, Ram-X, Classic-V, XD-4, VX-Pro4	Intermediate oval	Brand [16]
Arai	Other models	Intermediate oval	Brand [16]
Shoei	RF-1400	Intermediate oval	Retailer [17]
Shoei	GT-Air 3	Intermediate oval	Retailer [18]
Shoei	Neotec 3	Intermediate oval	Retailer [19]
Shoei	Hornet X2	Intermediate oval	Retailer [20]
HJC	RPHA 12	Intermediate oval	Retailer [21]
HJC	i11	Intermediate oval	Retailer [22]
HJC	RPHA 71	Intermediate oval	Retailer [23]
Bell	Race Star Flex DLX	Intermediate oval	Retailer [24]
Bell	Qualifier	Intermediate oval	Retailer [25]
Bell	MX-9 Adventure	Intermediate oval	Retailer [26]
AGV	K6 S	Intermediate oval	Retailer [27]
AGV	K1 S	Intermediate oval	Retailer [28]
Schuberth	C5	Intermediate oval	Retailer [7]
Schuberth	E2	Intermediate oval	Retailer [29]
Schuberth	E1	Intermediate oval	Retailer [30]
Schuberth	C3 Pro	Intermediate oval	Retailer [31]
Shark	EVO ES	Round oval	Retailer [32]
Scorpion	EXO-R430	Intermediate oval	Retailer [33]
Scorpion	EXO-AT960	Intermediate oval	Retailer [34]
Scorpion	EXO-GT930	Intermediate oval	Retailer [35]
Scorpion	EXO-R1 Air	Intermediate oval	Retailer [36]
Klim	Krios Pro	Intermediate oval	Retailer [37]
Klim	TK1200	Intermediate oval	Retailer [38]
Alpinestars	Supertech M10	Intermediate oval	Retailer [15]
Alpinestars	Supertech M8	—	No source found
Fly Racing	Formula CC	Intermediate oval	Retailer [39]
Fox Racing	V3 RS	Intermediate oval	Retailer [40]
Troy Lee Designs	SE5	Intermediate oval	Retailer [41]
6D	ATR-2	Intermediate oval	Distributor [42]
LS2	Citation II	Intermediate oval	Retailer [43]
Nexx	X.Vilijord	Intermediate oval	Retailer [9]
Nexx	XR3R	Intermediate oval	Retailer [44]
Nexx	Other models	Intermediate oval	Brand [45]
Sena	Stryker	Intermediate oval	Brand [46]
Sena	Impulse	Intermediate oval	Brand [47]
Icon	Airflite	Long oval	Brand [48]
Icon	Airform	Intermediate oval	Brand [49]
Biltwell	Gringo ECE 22.06	Round oval	Retailer [50]
Biltwell	Lane Splitter	Round oval	Retailer [51]
Highway 21	9mm	Round oval	Retailer [52]
Highway 21	.357	Round oval	Retailer [53]

Brand sizing notes

Arai: Arai makes three interior shapes. Intermediate oval is its standard shape; the Signet-X is long oval and the Quantum-X is round oval. All other models use intermediate oval. [16] Start with your measured size, then try all three Arai interior shapes. Depending on your head shape, you might fit a smaller helmet than your measured size. [54] Peel-away temple and cheek pad layers and optional pad thicknesses let you micro-fit the interior. [55]
Shoei: Measure 2 cm above the eyebrows, 2 cm above where the ears join the head, and around the most protruding point at the back. If you fall between two sizes, try the smaller size first. [3] A helmet size can't be identified by circumference alone, and the same size can feel different across Shoei models. [56] If the helmet moves around easily it is too big: try a smaller size or thicker pads. If you feel pressure on part of your head it is too small: try a larger size or thinner pads. [57] Hornet X2: RevZilla reports that customers have found it runs slightly small and recommend sizing up if between sizes. [20]
HJC: Measure about 1 in (2.5 cm) above the eyebrows. If your head size falls between two helmet sizes, try on the larger helmet first and then the smaller size. [12] HJC says its size chart is only a reference; always try the helmet on. [2]
Bell: Measure about 1 in (2.5 cm) above the eyebrows, level and snug but not tight, at the widest point. Measure twice and use the larger reading. [1] Optional cheek pad and top liner sizes are available for many models; riders with wider or narrower faces may need a different cheek pad size. [58]
AGV: Measure around the head where it is widest, at about the midpoint of the forehead above the eyebrows. Charts differ by model. [8] RevZilla's AGV FAQ says most AGV models fall between intermediate oval and round oval, with a back that is wider than the front. [59]
Schuberth: Schuberth's Individual program sells custom-fit head pads for C5, E2 and J2: a round-head pad (thinner sides, thicker back) and a long-head pad (thicker sides, thinner back) for extreme head shapes. [60] Schuberth's chart runs about 1 cm smaller per letter than many brands (SM is 54-55 cm, MD 56-57 cm), so don't assume your usual letter size. [7] C3 Pro: RevZilla reports that customers have found it runs small and recommend sizing up if between sizes. [31]
Shark: If you are between two sizes, Shark generally advises the smaller size, because the interior foam compresses over time. Pick the smaller size for a snug, racing-type fit or the larger for touring comfort. [10]
Klim: Klim publishes a separate whole-centimeter head chart for each helmet model, with multiple cheek pad sizes. [61]
Fox Racing: If your measurement falls between sizes on the chart, Fox recommends sizing up. [13]
6D: If your head size falls between two sizes, 6D says to try the smaller one first; pads and liners can often be adjusted. [11]
Nexx: NEXX helmets are designed to fit an intermediate-oval head form. [45] X.Vilijord: RevZilla reports that customers have found it runs small and recommend sizing up if between sizes. [9]
Biltwell: If you feel pressure or discomfort, especially at the forehead or temples, test-fit a larger helmet. If it moves easily without moving the skin on your forehead and cheeks, try the next size down. [62]
Highway 21: 9mm: RevZilla reports that customers have found it fits big and recommend sizing down if between sizes. [52]

Retailer customer reports (like "runs small") are what buyers told the retailer, not brand claims.

Measure once. We'll do the chart math.

Save your head size and shape in your profile, then browse helmet deals filtered by head size and shape. We'll show your size on each brand's chart where we have one, plus a shape match note. Join the waitlist →

Sources

Size charts and shapes change. Always check the chart on the exact product page before you buy. Last checked October 18, 2026.