Ski Helmet Guide: How to Size One, Which Standard to Look For, and When to Replace It

Run a tape measure around the widest part of your head, roughly two fingers above your eyebrows. The measurement in centimetres is your helmet size.

If you fall between sizes, take the smaller one. Most helmets have an adjustment dial at the back that tightens by a few centimetres — but nothing shrinks a helmet that is too big.

Test one: put the helmet on without fastening the chin strap and tip your head forward. It should stay on. If it falls off, it is too big and will shift on impact — protecting nothing.

Test two: with the helmet on, turn your head side to side. The helmet should move with your head rather than sliding on your scalp, and there should be no pressure point on your forehead. Pressure becomes a headache within a couple of hours.

Check the fit with your goggles too. An open gap between helmet and goggle leaves your forehead cold and makes the goggles harder to keep in place.

In Europe the relevant standard for ski and snowboard helmets is CE EN 1077. It splits into two classes: Class A covers more of the head and offers higher protection; Class B covers less, leaving the ears open, and is lighter.

A cycling or skateboard helmet is not a substitute. Ski helmets are tested differently for impact absorption at low temperatures, for abrasion against snow and ice, and for goggle compatibility.

Technologies such as MIPS add a low-friction layer inside the shell to reduce rotational forces. They are not required, but if one is offered, take it.

A helmet loses its protection after a single serious impact. The inner foam absorbs the blow by crushing permanently; even with no visible damage, it will not perform the same way twice.

So a helmet you hit your head in should be replaced even if it looks fine. With rental gear we apply that rule ourselves: a helmet that has taken an impact leaves the inventory and is never rented again.

Even undamaged, manufacturers generally give helmets a five-year service life — the foam and shell degrade over time.

Ski helmets look much alike, and most of what separates them by price is invisible. Knowing what to look at makes the choice straightforward.

Ventilation is the most tangible difference. A helmet with adjustable vents can be closed on a cold morning and opened in the afternoon. A helmet with no ventilation cooks you in spring; one with permanently open vents chills you in January.

The liner should be removable. That allows it to be washed, and swapping liner thickness is also how fit is fine-tuned. On our rental helmets, liners are removed and disinfected after every rental.

Ear pads detach on most models, which is comfortable for spring skiing — but anyone wanting Class A protection should choose a model with fixed ear coverage.

MIPS and similar systems place a low-friction layer between shell and head that slides a few millimetres, reducing the rotational force transmitted in an angled impact. Not required, but take it if offered.

A child's helmet is not a scaled-down adult one, and there are two meaningful differences.

The first is coverage. Children's helmets extend further around the back and sides of the head, because children fall backwards and sideways far more than adults do.

The second is the chin strap. Children's helmets usually have a magnetic or one-handed buckle, which lets a child fasten and remove the helmet unaided — and in practice that markedly increases how often it actually gets worn.

Sizing up so they grow into it is particularly dangerous with helmets. A loose helmet shifts on impact and protects nothing. A child's helmet is included free with our junior ski sets, and we swap sizes free of charge if the child grows during the season.

One more thing: if your child will not wear a helmet, it is usually because you are not wearing one. Children copy examples, not rules.