It’s important to know how to fit a bike helmet for a child.
If your child’s helmet is not comfortable, they are less likely to wear it.
A properly adjusted helmet will fit your child’s head well and be much more comfortable.

How Do I Know If My Child’s Bike Helmet Is Fitted Correctly?

Buy the right size helmet and follow the steps listed in our article to adjust their helmet so it is safe and comfortable for them to wear.

The most important thing to think about comes before fitting bike helmets for children. You must make sure to buy the correct size helmet. Children’s head sizes vary.

You can find information about buying a bike helmet for a 10-year-old or a bike helmet for a 5-year-old, or for whatever age your child is. We do not recommend following this information, especially if this is the first time you are buying a bike helmet for a child.

Buying a helmet based only on the age of the child is not sufficient as not all children have the same sized heads at the same age.

The most effective and safest way to decide on the right size helmet for your child is to measure their head. This will give you the approximate size to look for.

To do this take a fabric measuring tape and wrap it around the head about 2 cm (1 inch) above the eyebrows. Measure from here, making sure the tape is level all the way around.

If you don’t have a measuring tape use some string instead. Mark or cut the string and then straighten it out next to a tape measure or ruler to get the circumference.

After measuring your child’s head circumference, you’ll have a good starting point for helmet sizes. You can then compare this measurement to the helmet manufacturer’s sizing table and pick an appropriate helmet for your child.

A Well Fitted Helmet

Helmets are designed to last for a while so they have variable sizing. To make sure the helmet fits your child, it will come either with multiple helmet pads or a fit ring (or both).

With skate-style helmets, you generally have to rely on padding. Other cycling helmets will have a “universal fit ring” at the back of the helmet that tightens or loosens the helmet.

The helmet is appropriately snug when your child can shake and roll their head without the helmet moving around. The front of the child’s bike helmet should be aligned just above their eyebrows.

If it is tilted backward and you are seeing large expanses of their forehead, it needs to be adjusted. You want the helmet to be comfortably touching their head all the way around.

It should be level and stable enough to resist even violent shakes or hard blows and stay in place. It should be as low on the head as possible to maximize side coverage, and held level on the head with the strap comfortably snug.

A correctly fitted helmet should be worn facing the right way (it’s amazing how many people get this wrong.) It should not be worn on the back of the head because the forehead will be exposed. This will not protect your child if they go over the handlebars face first. If the front of the helmet were to be pushed further back as the result of an accident the straps could cause choking or bruising.

1. Make Adjustments to the Fitting Pads or Ring

Many children’s bike helmets have a fitting ring rather than side pads for adjustment.  These one-size-fits-all models require that you begin by adjusting the size of the ring. 

Helmets that fit with pads come with at least one set of foam fitting pads. If the helmet came with a second set of thicker pads it can be used to customize the shape. For starters, you can often remove the top pad entirely or use the thinnest ones. This lowers the helmet on the head,  bringing its protection down further on the sides. It may reduce the flow of cooling air slightly, but probably not enough to notice.   

Adjust the side fit pads by using thicker pads if your child’s head is narrow and there is a space, or add thicker pads in the back for shorter heads. You may also move pads around, particularly on the “corners” in the front and rear. Leave some gaps to improve airflow. The pads should touch your child’s head evenly all the way around, without making the fit too tight. 

2. Adjust the Chin Straps

Place the helmet on your child and fasten the buckle. 

Check each of these things:

  • When your child looks up they should barely be able to see the front rim of their bike helmet. 
  • The Y of the side straps should meet just below their ear
  • The chin strap should be snug against their chin. When they open their mouth very wide they feel the helmet pull down a little.


With the helmet in position on their head, adjust the length of the rear straps. Then adjust the length of the front straps. The straps should make a Y shape under their ear. You may need to slide the straps across the top of the helmet to get the length even on both sides. Then adjust the length of the chin strap so it is comfortably snug. If it cuts into your child’s chin and is not comfortable, it is too tight. 

Now pay attention to the rear stabilizer if the helmet has one. It can keep the helmet from jiggling in normal use and make it feel more stable, but only a well-adjusted strap can keep it on in a crash. 

When you think the straps are about right, have your child shake their head around roughly. Then put your palm under the front edge and push up and back. Can you move the helmet more than an inch or so from level, exposing their bare forehead? Then you need to tighten the strap in front of their ear, and perhaps loosen the rear strap behind their ear. The two straps should meet just below their ear. Now reach back and grab the back edge. Pull up. Can you move the helmet more than an inch? If so, tighten the rear strap.  

For a final check, look in a mirror or look at the wearer whose helmet you are fitting. Move the helmet side to side and front to back, watching the skin around the eyebrows. It should move slightly with the helmet. If it does not, the fit pads are probably too thin in front or back. 

When you are done, your child’s helmet should be level, feel solid on their head and, very importantly, be comfortable. If their helmet is uncomfortable they are not likely to want to wear it. It should be well adjusted and comfortable enough for them to forget they are wearing it after a while.

You must be sure the child removes the helmet before climbing trees and playing on playground equipment. Otherwise there is a risk of catching the helmet and possibly creating problems! 

This doesn’t happen in normal bike riding, even in crashes, but it can happen while climbing trees or playground equipment.

Check Their Helmet Often

Adjusting your child’s helmet once isn’t enough. The straps will loosen, especially if your child carries their helmet by the straps. Keep an eye on the fit. Is the chin strap loose? Is the helmet crooked on your child’s head? If so, it’s time to tighten things back up. I  make sure to do this a couple of times a month, and more often if needed. 

Teach your child to care for their helmet and look after it well. Helmets can become damaged when dropped frequently and will be less effective in the case of an accident. Even if there are no visible signs of damage, the integrity of the helmet may be damaged. 

From time to time check the helmet for visible signs of wear. Look for cracks in the foam and outer shell. Don’t leave helmets laying around in the sun or where they may get something dropped on them. Extreme heat and extreme cold can damage helmet materials, so store them well. Remember to clean them from time to time as well so they stay looking nice and smelling good.

How Do I Know If My Child’s Bike Helmet Is Fitted Correctly?

It’s important to know how to fit a bike helmet for a child. If your child’s helmet is not comfortable, they are less likely to wear it. A properly adjusted helmet will fit your child’s head well and be much more comfortable.