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Most current premium helmets come in 3 to 5 shell sizes, while many budget and mid-range models use only 2 or 3. In our table of 24 current helmets, the Shoei RF-1400, Shoei X-Fifteen, Arai Corsair-X, Arai Regent-X, Arai XD-5 and Bell Race Star Flex DLX list 5 shells, and the HJC i10, Klim Krios Pro, Icon Airform and Schuberth C5 list 2.
This page is research-based. We did not test these helmets. Shell counts, size ranges and certifications come from manufacturer pages and retailer spec pages (mostly RevZilla, plus Cycle Gear, J&P Cycles and HJC’s US site). If we couldn’t confirm a number, we left the helmet out.
What is a helmet shell size?
The shell is the hard outer part of the helmet. The helmet size (XS, SM, MD and so on) describes the inside fit, which is set by the thickness of the EPS foam liner and comfort padding. One shell is usually shared by two or more helmet sizes.
If a model has 2 shells, an XS and a large might sit in the same outer shell, with the XS simply getting a thicker liner. If a model has 5 shells, each size is much closer to its own shell. For example, Cycle Gear lists the Schuberth C5’s two shells as XS-LG and XL-3XL, while J&P Cycles lists the HJC RPHA 1N’s four shells as XS, SM-MD, LG and XL-2XL.
Motorcycle helmet shell sizes by model
| Helmet | Type | Shell sizes | Size range | Certification (US model) |
|---|---|---|---|---|
| Shoei RF-1400 | Full face | 5 | XS-3XL* | DOT, Snell M2025 |
| Shoei X-Fifteen | Full face (race) | 5 | XS-2XL | DOT, Snell M2025, ECE 22.06 |
| Shoei GT-Air 3 | Full face (touring) | 3 | XS-2XL | DOT |
| Shoei Neotec 3 | Modular | 3 | XS-2XL | DOT |
| Arai Corsair-X | Full face (race) | 5** | XS-2XL | DOT, Snell |
| Arai Regent-X | Full face | 5** | XS-2XL | DOT, Snell |
| Arai XD-5 | Adventure | 5** | XS-2XL | DOT, Snell M2025 |
| Bell Race Star Flex DLX | Full face (race) | 5 | XS-2XL | DOT, Snell |
| Bell Qualifier DLX MIPS | Full face | 3 | XS-3XL | DOT |
| Bell SRT Modular | Modular | 3 | XS-3XL | DOT |
| Bell Bullitt | Full face (retro) | 3 | XS-2XL | DOT |
| HJC RPHA 1N | Full face (race) | 4 | XS-2XL | DOT, ECE 22.06, FIM |
| HJC RPHA 12 | Full face (sport) | 4 | XS-2XL | DOT, ECE 22.06 |
| HJC F71 | Full face (sport touring) | 3 | XS-2XL | DOT, ECE 22.06 |
| HJC i91 | Modular | 3 | XS-5XL | DOT |
| HJC i10 | Full face | 2 | XS-5XL | DOT; Snell M2020D (XS-2XL) |
| AGV K6 S | Full face | 4 | XS-2XL | DOT, ECE 22.06 |
| AGV Pista GP RR | Full face (race) | 4 | XS-2XL | DOT, ECE 22.06, FIM |
| Scorpion EXO-R1 Air | Full face (sport) | 3 | SM-3XL | DOT, ECE 22.06 |
| Scorpion EXO-GT930 Transformer | Modular | 3 | XS-3XL | DOT, ECE 22.05 |
| Icon Airflite | Full face | 3 | XS-3XL | DOT, ECE |
| Icon Airform | Full face | 2 | XS-3XL | DOT, ECE |
| Klim Krios Pro | Adventure | 2 | XS-3XL | DOT, ECE 22.06 |
| Schuberth C5 | Modular | 2 (XS-LG, XL-3XL) | XS-3XL | DOT |
Sources: RevZilla product spec data, Cycle Gear, J&P Cycles, Team Motorcycle, Fortamoto, Louis and HJC USA, checked November 2026. *RF-1400 3XL is offered in select colors only. **Arai does not publish shell counts on its US site; the figure is RevZilla’s listed spec. Certifications differ by market, so check the label on the helmet you buy.
Why the number of shell sizes matters
Smaller heads get a smaller helmet
This is the main benefit. With few shells, a rider who wears an XS or SM ends up in a shell built around a medium or large head. The result is a helmet that looks oversized, catches more wind and puts more mass farther from the neck. More shells mean the smallest sizes get their own, more compact shell. If you wear an XS or SM, start with our guide to the best motorcycle helmets for small heads.
Lower profile and less “mushroom head”
A shell that is too big for your head makes the helmet sit wide and tall. Riders call this the mushroom look. It is mostly cosmetic, but a bigger shell also has more frontal area for wind to push on at highway speed.
Weight
A smaller shell uses less material and less EPS, so it weighs less. Manufacturers usually quote weight for one size (often MD), so the helmet you buy in XS may be lighter than the listed figure and a 2XL may be heavier.
Large heads benefit too
At the top end, a dedicated large shell can keep liner thickness where the designers want it, instead of stretching a mid-size shell to fit. Range matters as much as shell count here: the HJC i91 and i10 run up to 5XL, which few helmets do. See our best helmets for big heads for more options.
What shell count doesn’t tell you
More shells do not automatically mean a safer helmet. Every helmet in the table meets at least DOT, and the certification on the label matters more than the shell count. Fit and head shape matter more too. A 5-shell helmet with the wrong internal shape for your head will still fit poorly. Our helmet safety ratings guide explains what DOT, ECE 22.06 and Snell test.
Helmets with the most shell sizes
These picks stand out for shell count or size range, based on published specs. Prices are approximate RevZilla or manufacturer list prices and change often.
1. Shoei RF-1400: best for small heads
The RF-1400 lists 5 shell sizes and runs from XS to 3XL in select colors. It carries DOT and Snell M2025 on the US model. With 5 shells across that range, small and medium sizes each sit in a shell close to their own size. RevZilla lists it at about $550 ($$$).
2. AGV K6 S: best 4-shell option under $600
Louis lists the K6 S with 4 shells (XS-S, M, L, XL-XXL), and RevZilla lists the US model as DOT and ECE 22.06. It covers XS to 2XL. RevZilla lists it at about $510 to $550 depending on finish ($$$).
3. HJC i91: best modular for big heads
The i91 is a DOT modular with 3 shell sizes and a size range from XS to 5XL. That range is rare for a flip-up. RevZilla lists it at about $270 ($$).
4. HJC i10: best budget pick for very large heads
The i10 uses only 2 shells, but it runs from XS to 5XL. HJC USA lists it as DOT and Snell approved, with 3XL to 5XL marked DOT only. HJC’s MSRP is $164.99 ($). For small heads, a helmet with more shells is a better match.
How to find your shell size
- Measure your head. Wrap a soft tape around the widest part, about one inch above your eyebrows. Our motorcycle helmet size calculator turns that number into a size.
- Find your helmet size on the brand’s chart. Sizes vary by brand, so use the chart for the exact model.
- Check which shell that size uses. Retailers like RevZilla list the shell count in the specs, and some (such as Cycle Gear for the Schuberth C5) say which sizes share each shell. If you sit at the bottom of a shell’s range, your helmet will look and feel bigger than one at the top of the range.
- Try it on. Wear it for 15 to 30 minutes and look for pressure points. Our guide on how to size and buy a helmet covers the full fit check.
Shell count and weight go together. More shell sizes keep small helmets light; see how that plays out in our list of the lightest full-face motorcycle helmets.
FAQ
How many shell sizes should a motorcycle helmet have?
Three is common for mid-range and premium helmets. Four or five is typical of high-end race and sport models from Shoei, Arai, Bell, HJC and AGV. Two shells is common on budget helmets but also shows up on some premium models, such as the Schuberth C5.
Do more shell sizes make a helmet safer?
Not by themselves. Safety comes from meeting a standard such as DOT, ECE 22.06 or Snell, and from correct fit. More shells mainly help with fit, profile and weight in the smallest and largest sizes.
Which helmets come in 5XL?
In our table, the HJC i91 and HJC i10 both run to 5XL. Most other models stop at 2XL or 3XL.
Are XS and SM helmets the same outer size?
Often, yes. On many helmets XS and SM share a shell, as on the AGV K6 S (XS-S shell). On the Schuberth C5, XS through LG share one shell. The HJC RPHA 1N gives XS its own shell.
Where can I find a helmet’s shell count?
Check the product specs on the manufacturer’s site or a major retailer. Some brands, including Arai in the US, don’t list it on their own site.
If you have a small or very large head, shell count is worth checking before you buy. Measure first, find your size on the brand chart, then pick a model whose shells and size range fit you.
