Having trouble finding a motorcycle helmet big enough to fit?
Here's information on motorcycle helmets for very large sized heads, defined as XXXL and above.
First check out the very large helmet size chart below
If you have any tips on where to find very large sized motorcycle helmets and/or custom made helmets, please send them to and I'll post the information for others to use.
Extra-Large Sized Motorcycle Helmet News: See the wBW AFX Magnus 3XL-4XL helmet review.
More tips on sources for extra-large sized motorcycle helmets from webBikeWorld visitors in the comments section below
From "J.C.": "When measured according to most sizing charts my head circumference comes out to 26.5 inches and 10 inches from top of head to bottom of chin. AFX offers a 4XL, but when ordered it was smaller then the HJC 3XL. Have tried HJC, AFX and THH 3XL in open face and full face. Haven't tried Zeus helmets yet. Will look them over and see what they offer."
See below for more wBW visitor recommendations for very large sized motorcycle helmets.
From "J.C.": Bell Helmets had a line of helmets that were apparently called the Fathead, King Size or King Head. This is now called the Bell M3 Xtra, a large shell helmet that is actually designed for auto racing.
It is available in hat sizes 8, 8-1/4 and 8-1/2 (XXL, XXXL and XXXXL). It carries a Snell Snell 2005 Certification and is made in the U.S.A. Bell also has an open-face helmet in size 8-1/4 (XXXL)
Also, Harley Davidson has its own helmet line and apparently they offer an open face, I believe is called Road Classic Open Face, that goes to a 4XL. When looking at their sizing charts the 4XL covers head size from 26 3/8 inches to 26 3/4 inches.
"...I have found helmets that can fit heads that are bigger than 26 inches. My head is about 25 and a half inches so, this one fits me like a glove. Granted this is an automotive helmet and all but, this guy at Snell Memorial told me that many motorcyclists use it if they have a huge dome like myself.
It is also costly, almost five hundred dollars but hey, if someone is going to gripe about keeping their head from smashing, watermelon style, they shouldn't be riding.
It is Snell rated at SA so it is good for motorcycling and it is fire resistant and all like that, making it consistent with automotive racing." It's the Bell "Fathead" in sizes 8 to 8-1/2, head diameters of 25-1/8" to 26-1/4" (64 to 67 cm). Also look for a similar helmet, listed as the Bell M3 Xtra.
From "G.M.": "I've been very happy with the Arai XXXL Signet. My head shape is a classic "long oval" so I'm a good match for their L.O. (long oval) design. There's never been a "red forehead" problem. I've owned two over the last 10 years and I look forward to trying their new XXXL Profile helmet.
A plus for the XXXL Arai Signet/Profile is the availability of several colors & graphic designs. You don't have to settle for a boring white design." Unfortunately, Arai no longer makes the Signet."
Clothing and helmet size charts for a general guideline to finding your clothing or helmet size.
|Head Circumference||Hat Size||Approx. Helmet Size|
|19-5/8 to 20-1/8||50 - 51||6 to 6-3/8||XXS|
|20-1/4 to 20-7/8||52 - 53||6-1/2 to 6-5/8||XS|
|21 to 21-5/8||54 - 55||6-3/4 to 6-7/8||S|
|21-3/4 to 22-3/8||56 - 57||7 to 7-1/8||M|
|22-1/2 to 23-1/8||58 - 59||7-1/4 to 7-3/8||L|
|23-1/4 to 24||60 - 61||7-1/2 to 7-5/8||XL|
|24-1/8 to 24-7/8||62 - 63||7-3/4 to 7-7/8||XXL|
|25 to 25-5/8||64 - 65||8 to 8-1/8||XXXL (3XL)|
|26-3/8 to 26-3/4||67 - 68||8-3/8 to 8-1/2||XXXXL (4XL)|
|27 to 27-1/2||69 - 70||8-5/8 to 8-3/4||XXXXXL (5XL)|
NOTE: All sizes are approximate and will differ (sometimes dramatically) between brands.
From "J.C." (October 2015): "Just a quick note that the Arai Quantum-ST Pro in XXXL shell may be of interest to riders like me with very large long oval heads.
I was finally able to find a helmet that I could get on in the HJC 5XL. But the new Arai specifically calls out its long oval shape (and it is apparently 5mm longer than the previous model).
Anyway, I can get it on. A much better helmet than the HJC and actually legal for me to use in Europe.
That said, the comfort liner doesn't fit me but I am working on a bespoke option. The shell and Styrofoam are fine.
You can get any colour you want so long as you want black or white. No idea if the Signet (USA version of the Quantum-ST) will be the same."
From "J.T." (August 2014): "The HJC CL-MAX II (review) goes up to 5XL. I bought the 4XL. It is just right. I wear a size 8 in a fitted "official" NFL or MLB ball cap."
From "G.M." (August 2013): "Jug heads of the world rejoice! Arai has released their new XXXL Defiant helmet...and it's a perfect replacement/upgrade for your old long-oval Profile or Signet! It arrived today from RevZilla...just tried it on...BLISS! It even includes a standard clear Pinlock visor."
From "J.W." (June 2012): "I just bought an HJC CL-MAX II helmet in size 5XL According to their sizing charts it should fit up to a 27-5/8 head, but I doubt that...
This is the review I just put on Amazon: This Helmet is big and comfortable. I wear an 8 1/2 hat, oval shaped head and have a long face.
The foam at the top of this 5XL helmet fits my head, and my chin is actually in the helmet. I did have to remove the cheek pads to be able to wear my glasses, but they snap right out.
All the vents and the chin release work easily with one hand, even wearing gloves. Fairly quiet on the freeway. Probably quieter with the cheek pads.
Good fit and finish, especially for the price! I also own the Vega in 5XL which is comfortable, but my lips are up against the chin piece. The HJC has plenty of room in the front and the visor seals better. Hope this helps someone else choose a helmet... Thanks!!!"
From "C" (December 2011): "My head measure 59 cm ... but trying on several 2XXL and one 3XXXL that barely fit, there was no way a 3X was correct. All were so tight, no way I could stand to be helmet for break-in.
I finally hooked up with K&N Yamaha (Tulsa, Oklahoma), which is the oldest Yamaha dealer in the USA. They knew what a good fit looks like.... not what it feels like on your head. There is a difference.
First they fit a helmet shell to my head that cradled my head properly, ignoring how it felt like on my head. Then they adjusted the internal padding to get the helmet comfortable enough to break in.
What ended up fitting me was a Bell RS-1 with thinner internal pads. Kudos to K&N Yamaha!!!
Folks with hard-to-fit heads, go to folks who know what a good fit on your head looks like. Then adjust to fit internally. Sorry there is no substitute for trying it on in person and having folks with lots of helmet fitting experience."
Editor's Note: The external shell shape doesn't always correspond with a head shape or size. I'd guess what they did was to recognize that your head was a "Slightly Narrow" shape (see the wBW Helmet FAQ) and then modified a Bell RS-1, which has that head shape, by changing the cheek pads.
The key point you make is that a good helmet brand can be adjusted by changing the cheek pad thickness or crown.
Many motorcyclists don't realize that this is an option, although you have to be looking at a higher quality helmet manufacturer that offers optional liner parts to make a bespoke fit.
From "R.H." (7/09): "I tried a HJC CL-Max (flip-up) in 3XL and it was small. I could squeeze it on, but there was no way it was going to "break in". Then I went to Cycle Gear in Bear, Delaware.
They were most helpful and we actually found a Shoei Multitec (review) in XL that almost fit. We special ordered a 2XL and it fit perfectly. Trust me, no other 2XL came close Give the Multitec a try."
From "M.C.C." (6/09): "After searching up and down the Internet, I was unable to find a helmet to fit my 26" head. I even tried a Bell M# Xtra, and it didn't fit because my head shape is a long/oval (9 1/8" front to back).
I then found out that AFX Helmets had a new model coming out in July 2009 called the FX-Magnus. I contacted the company and I was able to get my hands on one early. Fits me perfectly."
From "Fabio" in Italy (5/09): "I read in your site an useful guide to Very Large Helmets. I've always had this problem, unfortunately.
Luckily, a long time ago I found a Shoei helmet that fit me. Once I broke it in a way I couldn't fix it, I started to look for another comfortable helmet. It's been very hard but finally I found it; Shoei XR-1000 in size XXXL.
This is also known as the Shoei RF-1000 in the U.S.A.. Thanks Shoei (for making) 4 different shell sizes. Few do it.
I hope to be helpful for others that have the same problem."
From "D.K.": "Hi there, I would like to reply to your helmet guide for large headed people. I would like to say thank you for the leads on bike helmets and that they were very useful.
I have been searching for a helmet that will fit my 27" head for a long time & have had no luck until now.
With your helpful connections I found a helmet maker (Vega) that goes up to 27&1/2". Now I can ride feeling a lot safer with a helmet that will fit comfortably. Thank you very much."