How Should a Motorcycle Helmet Fit?

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Not wearing a motorcycle helmet is bad for your health. Wearing one that doesn't fit isn't as bad, but it can be dangerous and painful.

A helmet should fit the size and shape of your head, and it should also be snug around the crown of your head. If you can comfortably wear it around the house for an hour, it's a good fit. Some people are slightly in between sizes, but it should still fit properly.

With motorcycle helmets, one size does not fit all, and it's easy to buy the wrong sized helmet. Knowing how a motorcycle helmet should fit, what type of helmet you need, and the exact size of your head might save you a lot of trouble. Some other things you'll want to consider are Comfort and Padding.

My dad always bought me standard-sized dirt bike helmets with tons of padding for dirt biking. When I went to buy my first street bike helmet on my own, the guy asked me what my head shape was, and I told him, and he looked at me funny. That's when I found out I'm more of a "long oval." Since then, that's the type of shape, and it makes a big difference on long rides.  

In this article...

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How a Motorcycle Helmet Should Fit

Motorcycle helmets should be comfortable the first time you try them on, and they should never be too tight or too loose.

All you really need is:

  • The right size and shape for your head.
  • Proper protection to your head.
  • Something that feels light enough to look around freely without any discomfort.
  • The visor has to be very clear.

The wrong-sized helmet is uncomfortable and offers less protection. If it's too small, it may even cause a headache—the last thing you need when you're on a ride. If it's too cumbersome, you will have trouble turning your head. If it's too big, it will not offer the same protection. The first thing you should do is measure your head.

Measuring Your Head

It's essential to get an accurate measurement when buying motorcycle helmets online because manufacturers have slightly different sizes. Some online stores have apps that let you take a picture of the top of your head and upload it to determine the shape.

What you need:

  • Tape measure or cloth
  • A friend

The easiest way to measure your head is with a tape measure. It's easier to get an accurate measurement if someone else does it. Just wrap the measuring tape around your forehead, slightly above your eyebrows and ears. Make sure it's not too tight or too loose.

If you don't have a tape measure, you can use string or yarn and just wrap it around your head and pull it tight. Draw a line where the two ends meet, then measure that length with a ruler or measuring tape.

Size Charts

These charts are a general guide but most brands will have the same sizes. Always check the gear company's size charts, which is especially when buying online.  

Adult Sizing

SIZE CENTIMETER INCHES
2XS 51 - 52 20 - 20 1/2
XS 53 - 54 20 7/8 - 21 1/4
S 55 - 56 21 5/8 - 22
M 57 - 59 22 1/4 - 22 - 7/8
L 59 - 60 23 1/4 - 23 5/8
XL 61 - 62 24 - 24 3/8
2XL 63 - 64 24 3/4 - 25 1/4
3XL 65 - 66 25 5/8 - 26
4XL 67 - 68 26 3/8 - 236 3/4
5XL 69 - 70 27 1/4 - 27 5/8

Youth Sizing

SIZE CENTIMETER INCHES
S 49 - 50 19 1/4 - 19 3/4
M 51 - 52 20 - 20 1/2
L 53 - 54 20 7/8 - 21 1/4
XL 55 - 56 21 5/8 - 22

How should it Fit? Checklist for Trying on Your Motorcycle Helmet

The expanded polystyrene (EPS) Is the layer under the outer shell, and this is what absorbs the shock if you get into an accident. The padding can make it more comfortable if you want a more snug fit.

It should fit without Padding. Let me repeat that; the padding doesn't do anything but make it more comfortable. Don't worry too much if the helmet is a little too tight. Most of the helmets will form to the shape of your head after like 15 hours of riding.  

  • You should not be able to chew gum after the chin piece or chin strap is on.
  • If the helmet has a neck roll that should sit comfortably on your neck without too much pressure.
  • If you go for full face and cheek pads, they should be resting on your cheeks without causing discomfort.
  • Your pressure points should not be constricted.
  • If you have an open face with a chin strap, you can fasten it, and it should be tight enough to have two fingers in between
  • Lean forward and make sure it doesn't fall off your head
  • Shake your head from side to side it shouldn't move around; it should stay snug and comfortable like one of those foam sparring helmets

If everything on the checklist clears, wear it for about an hour and it should be good if it doesn't cause any discomfort. Always try it for a while first because you might not be able to return it. It's easy to get the wrong size if you are a noob (like I was), and you might not realize it until you hit high speeds.

Can You Make a Motorcycle Helmet Fit better?

Think of it as a shoe and a sock. You'd rather have it a little snug so it will expand than too loose, and padding just makes it fit better.

It should fit without it, but after you've broken in your helmet you might want a little more comfort, especially if you have big ears like me. If it is secure around the crown of your head, but your jaw can still move up and down a bit too much, you could try tightening the chin strap or using slightly thicker cheek pads.

Add More or Less More Padding.

You might be able to swap out the padding or get a new liner for free. It depends on the brand you buy it from. Cheek padding can help if you have a full-face helmet and want to adjust the fit. Even though there are only 3 basic head shapes, there are different jaw sizes. The shell sizes are a little different sometimes as well, so padding can also make a difference.

Adjust the Chinstrap

If you got a helmet with a chin strap, you can adjust it whether it's a ratchet strap or a D-ring. When you tighten the strap, make sure you can still fit two fingers in between it and your chin. When you bend over, it shouldn't fall off.

FAQ

What if the Helmet Fits Too Loose?

A loose helmet is probably more dangerous than one that's too tight. Loose helmets wall cause lift and put a strain on your neck. Besides that. The purpose of a helmet is to cushion and absorb impact. If it's too loose and you crash, your brain will rattle around, and you will suffer multiple impacts. If you got a helmet that's too loose, you need to get a new one right away. The main thing is that it should still grab your skin end fit snug on your crown. A little extra padding will help if it's not as snug as you'd like.

What if the Helmet is Too Small?

A small helmet can give you headaches, double vision, and discomfort. You'll probably notice the helmet is too small after a few short rides. It's going to be uncomfortable, and if you wear it for at least an hour, you might have red marks on your temples. You will definitely feel pain on your pressure points. If your home is too small, your head's going to before it's down at freeway speeds.

Does the Size of My Head Change?

Yes. The size of your head will change over time as you get older, or if you're doing steroids or something. Your skull will gradually get thicker as you age, so your head's going to get slightly bigger. This takes a long time, like you'll have to be 20 years older, but if you hit your head or get a dent in your head, you're definitely going to have to resize it.

Will My Helmet expand or contract After a While?

It should be replaced in 3 to 5 years anyways. In countries like India, everyone rides motorcycles, and the laws and safety standards are looser; you can probably find lots of people who have had the same helmet for 20 years. This is dangerous because the EPS is going to wear down by then. Even if you just wear it on weekends for a few years, it should probably be replaced. It's better to be safe than sorry.

What if I have a Lot of Hair

If you have long dreadlocks or a ton of curly hair, it's definitely going to affect your helmet's fit. I really don't know if it makes a difference, but from what I can gather, it's going to hurt if you crash and you have a bunch of hair. It's basically like making it fit with more padding, so your brain will rattle around more if you slam your head. Many people have dreadlocks and have a motorcycle, so I don't want to say anything wrong, but I'm not sure how safe it is.

About THE AUTHOR

Russ Crowley

Russ Crowley

Russ currently owns a Yamaha FZ6N and KTM RC 390. When it comes to vintage bikes, his favorite motorcycle is the feisty BMW R32. He also holds a particular interest in the LAMS segment and triple cylinders. Himself a riding enthusiast, Russ has had experience with racetracks from around the world including Willow Springs Raceway in California and the Imola Circuit in Italy.

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