First thing you need to determine your size is your head measurement. Wrap a soft tape measure around your head, just above your eyebrows to get the circumference. Then check that number against the size range on the box of the helmet you’re considering, to find out if you need a small, medium or large helmet.
Open helmet to largest setting
Use the adjustment mechanism on the helmet to open it to the largest size possible.
Try it on
Put the helmet on your head, being sure that the rim sits about one finger width above your eyebrows and the occipital lock is sitting on the occipital bone at the back of your head.
Using either the tool-free adjustment or a screwdriver, depending on the helmet, tighten the helmet until it’s snug and secure but still feels comfortable.
Try mask and chin strap
Do up the mask, making the sure the chin guard fits on or slightly under the chin. Fasten the chin strap. It should fit closely, but comfortably, with space to put a finger underneath it.
Check the overall fit
Now that the helmet is on your head, shake your head up and down and side to side, in yes and no motions. The helmet should stay snug on your head, not move independently.
Know when to replace it
Helmets don’t last forever. Keep an eye out for natural deterioration of the foam and any cracks on the surface that may occur with impact. Each helmet includes a sticker with a recommended expiry date. Although not required for Canadian safety standard you can use this as a guideline for when you should consider replacing your helmet.