How to Choose the Right Helmet for Your Head Size

As you ride the streets of Vietnam you’ll get the impression that any helmet goes!. Helmets are lined up in a variety of shades and for about $5 you can take one home. This piece of plastic crap is about as useful as no helmet at all. 

Some of the best motorcycle helmet options in Vietnam are; BELL, LS2, Yoho, and Andes. Andes is made in Vietnam and can sometimes be easier to find than other brands. For these options, you’ll need to search for reputable motorbiking equipment suppliers. Saigon has a few shops with quality gear and shopping online for a motorcycle helmet in Vietnam is getting easier.   

The biggest problem you’ll run into is supply. With heavy import taxes by the government and low local demand for higher-priced quality goods, the supply isn’t always there.  

How To Choose The Right Helmet For Your Head Size

(or how to buy a motorcycle helmet)

Buying a helmet is more than just looking at price tags and picking a paint job. Helmets have become highly technical pieces of equipment that can literally become the difference between life and death. Modern designs have safety features like impact-absorbing MIPS technology that cradles your head in a fall, right up to comfort designed ventilation and weight savings consideration. If your lid isn’t comfortable, you’re not going to wear it and even the safest motorcycle helmet in the world won’t help if it doesn’t fit right.

To help you navigate through endless options of head protection we’ll breakdown helmet styles, sizing, fitment, and how to find the best helmets in Vietnam.  


Helmet Styles

The style of motorcycle helmets you choose to wear is often dictated by the motorcycle you ride. Backpacking Vietnam on a scooter and riding to and from the beach, you’ll probably be ok with an airy open face lid. On a dirt bike like the Honda XR150, riding mostly single track or the muddy trails just outside of Saigon, a light and well-vented dirt helmet is good. The full face, modular and dual sport helmets are generally for adventure riders that are splitting their time between the roadways and backroads from HCM to Hanoi. As for the half shell, it’s reserved for people with no brain to protect! Kidding, but really, get something better than this. 

 half shell

Half Shell: The type of helmet you wear to cross the street with. If you ever got in an accident where your head actually needed to be protected, this Skull Cap isn’t going to do much for you.


  • Loads of ventilation.
  • Easy to remove and put on.
  • Comfortable fit.


  • Very basic protection.
  • No face protection.
  • The false sense that your head is safe.

Open Face: A step up from the Half Shell, an Open Face helmet is good for overall head protection but it still isn’t going to do much for your face. An ok choice for low-speed or scooter riding.


  • Loads of ventilation.
  • Easy to remove and put on.
  • Comfortable fit.


  • No eye protection.
  • No face protection.
  • Looking like an astronaut helmet.

Modular: A flip-up or modular style helmet is similar to a full face with one extra option. The helmet unlocks from the chin and flips up to expose your face when you’re NOT riding. The plus side of this is the rider can easily lift the face of the helmet and talk to people or walk into shops without taking the helmet off. 


  • Easier to get off than full face motorcycle helmets
  • Opens at the chin bar.
  • More functional for talking and hydration. 


  • Typically weighs more than a full face.
  • Noisier than a full face.
  • More moving parts of a motorcycle helmet mean more things that can fail.

full face

Full Face: The most protection you’ll find in a street helmet. Full face helmets wrap around your entire head, cushion the cheeks and have visors to protect the eyes. Provided the helmet fits properly this is the best protection you have against head injuries in the event of an accident. LS2 has a good range of full face helmets in Vietnam, check out some examples of full face helmets currently available.


  • The quietest full face helmet is more enjoyable than windy open face helmets at speed. 
  • Has a chin bar to protect the bottom of your face.
  • Eye protection all around.


  • Harder to get on and off.
  • Limited ventilation. 
  • Often the most expensive option.

dual sport

Dual Sport: Slightly different from a full face helmet, the dual sport helmet typically has the visor area cut large enough to accommodate goggles. Also, there is an additional peak on the top like a dirt helmet to help with sun glare. For the dual sport rider, this is a popular and versatile option to use. When shopping for a dual sports helmet for South East Asia, make sure it’s well vented.


  • Comfortable.
  • Better safety ratings than most dirt helmets.
  • Can use with goggles or a visor.


  • Less ventilation than a dirt helmet.
  • Peak on top can catch the wind at high speeds.
  • More restrictive than modular helmets.

Dirt Helmet: Usually the lightest weight helmet in every class but the Skull Cap, a dirt helmet is designed for off road use. These helmets are meant for lower speeds, are very well ventilated and usually come in a variety of loud colors. Wearing one of these light and vented dirt helmets available in Vietnam to rip up the singletrack is a good option.  


  • Good warm weather helmet.
  • Typically has plenty of ventilation.
  • Lightweight.


  • Not for use at high speeds.
  • Not always safety rated for road use.
  • Noisy.

dirt helmet

How To Know Your Head Type

Knowing the shape of your head helps to determine what helmet fits you the best. For the most part, people fall into three main shapes: round oval, intermediate oval, and long oval.

The easiest way to determine your head shape is to take a photo of your head from the top down. Have you ever seen the top of your head?

To Find Your Shape:

  1. Grab a friend and take a seat
  2. If you have no hair, perfect. If you do, hold it down as close to your head as possible.
  3. Have the friend take the photo standing directly above you.
  4. Compare it to the head shapes in the chart.

Tip: the average western head falls into the intermediate oval category.

head shape for helmet

Most everyone is one of these three head shapes. Knowing what shape you are will help with your helmet selection. 

How To Choose Helmet Size

Knowing your head size makes pre-selection and buying motorcycle helmets direct online easier. Most major manufacturers will have sizing charts for their helmets online. Once you know your head size you can narrow down your helmet options even better. For this, you’ll need your friend again. 

To Measure Your Head:

  1. Grab a flexible tape measure.
  2. Take the same seat as before.
  3. Have your friend measure around the crown of your head.
  4. Note the measurement and start shopping.

Tip: Don’t do this by yourself. You can’t see the back of your head to know if you truly have an even measurement all the way around. 

tape measure

What Does A Properly Fitting Helmet Feel Like?

Before you commit to buying a helmet you’ll want to wear it for as long as possible. If you know someone who has a similar helmet to the one you want to buy, perfect. Put it on for at least 20-mins, an hour is better. Watch t.v., work on your computer, or take your motorbike for a ride.. Just get the feel of it. 

The other option is to head to your local clothing and accessories shop and try on what they have, you’ll also get to know what other safety gear is available for Vietnam. If you’re at a motorcycle gear shop trying on helmets they aren’t going to let you leave the store. Narrow down the helmet(s) you want to buy and try them on. 

Continue to shop around with the helmet on. Moving around, looking out the side, shaking your head, all these actions will help determine if the helmet fits and you’re not purchasing a motorcycle helmet too big for you. The more time in the helmet the better. 

Is this helmet good for me? 

  • My helmet is snug all around and doesn’t shift when I turn or shake my head. GOOD :)
  • My helmet moves when I quickly move my head to one side. BAD :(
  • The cheek pads on my full face helmet squish my face slightly. GOOD:)
  • I can easily chew gum or eat with my modular/full face/dirt helmet on. BAD:(
  • I can use my peripheral vision to see beside me in this helmet. GOOD:)
  • I’ve been wearing my helmet for more than 20-minutes and I’m getting annoyed or a headache. BAD:(
  • I paid more for this helmet than I wanted, but I feel safe and confident riding. GOOD:)
  • I got this helmet used and it has some heavy scuff marks and a small crack. BAD:(

helmet size chart

Note: This particular chart is from Bell. You’ll want to check each manufacturer’s website to see what they consider to be a S-M-L etc. helmet. Even then, it won’t always be 100% accurate.

Understanding Helmet Safety 

DOT, SNELL, ECE, SHARP, MIPS, what do all these words mean when it comes to choosing the right helmet for your head? The first four are safety ratings accepted in different global markets. MIPS is a new type of technology designed for motorcycle helmet makers to add even more protection to your helmet. You can read our complete explanation on helmet ratings for a better understanding, as well as the brief description below.

TIP: In Vietnam, you can find $5 helmets with DOT stickers on the back. I might suggest this could be #FakeNews

  • DOT United States Department Of Transportation rating. This is the minimum standard rating. Better than no rating but not the best.
  • SNELL. A SNELL rating is tougher to obtain than DOT, you need to apply to SNELL for testing and meet higher criteria in order to sell SNELL certification. 
  • ECE. The Economic Commission for Europe. As standards change/improve you’ll see the ECE logo change. Originally it was ECE22, the latest standard is now ECE 22.05 
  • SHARP. The SHARP rating was developed as one of the motorcycle helmet standards UK for the Department For Transportation. Some of their testing is even more stringent than the ECE ratings.   
  • MIPS. In short, the Multi-direction Impact Protection System is a liner inside the helmet that craters your head in a crash allowing it to move slightly inside the helmet. 

Common Problems

  • I read the sizing chart and took a photo of my head but I’m still not sure what head size I am? You might not be an exact replica to the circle and oval shapes on the guide, but if you had your friend take a photo you should have a very good guess. If you’re from USA/OZ/UK there is a good chance you are shopping for intermediate oval helmets. 

  • I need glasses to see when I’m riding, should I get a helmet one size bigger? No, you should get a helmet that fits. Some helmets are specifically designed with cutouts for glasses or you can modify your padding to fit. Good helmet options for use with glasses in Vietnam are; LS2 MX437 - Dirt Bike Helmet, BELL Street SRT - Modular Helmet, and the BELL MX-Moto 9 - Dirt Bike Helmet.

  • I can’t get the helmet over my head even though the chart sizing said it would fit. Sometimes the neck or cheek protection is bulky and you’re unable to get your head in. For this, you can pull back the protection and slip your head in. If you try and your head still won’t go, perhaps you picked one of the helmets with small shell sizes. Go one size up! 

I can’t find the helmet I want in Vietnam. This is a common problem, but usually, a supplier can recommend something similar or let you know when they are getting stock in. If you end up buying a helmet online and it’s not exactly what you were looking for, just pay the shipping and you can return the unused helmet without any issue.