A new helmet will break in as you wear it and mould to the shape of your head. It should fit like a new pair of boots: snug, with a firm and even pressure all the way around.

Things to check for:

A snug fit with even, firm pressure around the entire head
No specific pressure points or gaps
Helmet locks onto the back of the skull
Helmet sits level on the head, covering the forehead leaving about an inch above the eyebrows
With the harness unfastened, the helmet should not rock forwards nor backwards
The chinstrap should sit just under the chin and gently touch the bottom of the ear lobe, avoiding the throat
You should be able to put a finger between the strap and your chin
The harness laces at the back of the helmet should be secured tightly
Wear the helmet for 5 minutes to give time for it to mould to your head and reveal any pressure points.

How to measure for a helmet.

Using a soft fabric measuring tape, wrap it around the widest part of your head (over your hair).

It should follow a line about 3/4 inch above your eyebrows, just above the ear line and around the bump at the back of your head.

Take the measurement in centimetres (cm) and repeat a couple of times for the most accurate sizing.

Compare your measurement to the size chart for whatever brand your interested in!