Motorcycle helmet size guide for Australian riders

Nearly every rider has owned one. The helmet that felt fine in the shop, turned into a headache forty minutes down the North West Coastal Highway, and has been sitting on a shelf in the shed ever since.

It usually wasn't the wrong helmet. It was the wrong size, bought off a guess.

Quick answer A motorcycle helmet fits correctly when it is firm and even all the way around your head, with no single painful pressure point, and will not rotate independently of your skin or roll off with the strap done up. Size it from your head circumference in centimetres against the manufacturer's own chart, and check it carries a certifying mark approved for road use in Western Australia.

Fit isn't a comfort question, it's a function question. A loose helmet moves at the exact moment you need it not to. A tight one gives you a reason to leave it at home. Somewhere between the two is a helmet that disappears on your head after ten minutes, and that's the one worth paying for.

This is how we size one across the counter in Geraldton. Measuring, reading a brand chart that disagrees with the last brand chart you read, the four tests that tell you the truth, what's actually legal to wear in WA, and what changes when you swap tarmac for dirt or hand a helmet to a nine-year-old.

Snug, Not Strangled: How a Motorcycle Helmet Should Actually Fit

A correctly fitted helmet is snug the whole way around, with the lining touching your head evenly and the cheek pads in firm contact with your cheeks. It shouldn't move independently of your head, and it shouldn't hurt anywhere.

That last part trips people up. Snug and painful are not the same thing, and a lot of riders talk themselves into a helmet that hurts because they've been told a tight helmet is a safe helmet. It isn't. It's a helmet you'll stop wearing.

Strap done up, run these four checks.

• The cheek test. Your cheeks should be pushed up a little, the way they are in every unflattering photo of you in a new helmet. If you can talk and chew with no pressure at all, the cheek pads are too thin for your face.
• The crown test. Slide a finger between the brow padding and your forehead. You shouldn't get much in there. What you're after is even contact right across the crown, with no single hot spot.
• The rotation test. Grip the helmet and try to turn it side to side, then nod it up and down. Your skin should move with it. If the helmet turns and your face stays put, it's too big.
• The roll-off test. Grab the back edge and try to roll the helmet forward off your head, then push the front up and back. If it comes off, or slides down over your eyes either way, it's too large. This is the one that matters most and it's the one almost everybody skips.

Then leave it on for 15 to 20 minutes before you decide anything. Pressure points are invisible in the first minute and unbearable by Northampton.

Too loose or too tight? The tells

Some of that is adjustable and some of it isn't, and it's worth knowing which is which before you spend money trying to fix it. Some helmets offer manufacturer-approved replacement cheek pads or interior liners for small adjustments. What they cannot do is turn the wrong shell or crown size into the right one. Follow the helmet manufacturer's fitting instructions, or ask a trained dealer.

Pressure in one place only, rather than evenly all round, usually points to shell shape rather than size. Worth raising with whoever is fitting you, because the fix is a different brand, not a different size.

How to Measure Your Head for a Motorcycle Helmet

Nobody has ever owned a soft tape measure at the moment they needed one. It's fine, there's a workaround below, and the whole job takes two minutes.

Soft tape, level, about 2.5cm above your eyebrows and around the widest part at the back. That number in centimetres is what every helmet size chart in the world is built on, so it's worth two minutes of care.

• Use a soft dressmaker's tape. If all you've got is a builder's tape, run a bit of string around your head, mark it, then measure the string.
• Measure two or three times and take the largest number. The tape moves a lot more than your head does.
• Get someone else to do it if you can. Measuring your own head in a mirror is how people end up a centimetre out, and a centimetre is a whole size.

Write the number down and keep it in your phone, because you'll want it in a shop, on a website, and eighteen months from now when you're replacing this helmet and can't remember. You'll use it against every brand chart you ever read, and they will not all give you the same answer.

What Helmet Size Do You Need? Your Answer Changes With Every Brand

Here's the part nobody enjoys. You've been a large since you were nineteen, and you'd rather not revisit it. The chart doesn't know that, and the next brand's chart doesn't either.

There is no universal helmet size chart. Sizing is set by each manufacturer, which means the same head can be a medium in one brand and a large in the next, and neither of them is wrong. Always use the chart for the brand and the model you're actually buying.

Leatt is the brand we stock most deeply, so here's how they size their adult helmets:

Other brands sit half a size off that, and shell shape matters as much as the number on the chart. Some run long and narrow, some run rounder. Two helmets both marked large can feel like completely different objects. Carrying a size across from a brand you wore five years ago is how a rider who has been a large for a decade ends up in a helmet that fails the roll-off test.

If your measurement lands between two sizes, try both and follow the chart for that exact model. The right call depends on crown fit, your head shape and the adjustment options the manufacturer approves. Don't assume the smaller one is automatically right. That's an old piece of advice that only holds for some helmets.

The Sticker That Keeps You Legal: Which Helmet Safety Standard Do You Need in Australia?

Two questions get tangled together here, and the confusion costs people real money. One is what's legal. The other is what's good. A helmet can clear the first bar and be nothing special on the second, and the sticker on your chin strap only ever answers the first one.

What's legal in Western Australia

Four standards. That's the whole list. They sit in the Road Traffic Code (Protective Helmets) Notice 2021, made under regulation 244 of the Road Traffic Code 2000 and gazetted on 16 July 2021:

• AS 1698:1988, Protective helmets for vehicle users
• AS/NZS 1698:2006, Protective helmets for vehicle users
• UN ECE 22.05, but only where the helmet was manufactured in, or imported into, Australia before 3 January 2024
• UN ECE 22.06, the current European standard

The helmet also has to carry the mark for it. For the two Australian standards the notice names who can grant that mark: TÜV Rheinland Australia, SAI Global Australia, Global-Mark or the British Standards Institution. No label, not approved. The box doesn't count and the product listing doesn't count. The sticker counts.

Rider and passenger both, strap done up. The WA Road Safety Commission puts getting it wrong at $550 and 4 demerit points.

Now the one that catches people out. A helmet wearing nothing but a US DOT sticker, or nothing but a Snell certification, is not approved for WA roads. Not "probably fine". Not approved. Some genuinely well-built helmets fall into this hole, and they tend to be the ones that looked like a bargain on an overseas site at two in the morning. Check the strap before you check the price.

Reading the label, which is smaller than it should be

On an ECE helmet the approval label is sewn into the chin strap. You're looking for a circle around the letter E followed by a number, and that number tells you which country granted the approval, not where the helmet was built. Next to it sits the approval number, and the first two digits are the whole story: 06 means ECE 22.06, 05 means ECE 22.05. After that comes a letter for the type of protection. P is a full face with a chin bar that has been tested as protective. J is an open face.

What ECE 22.06 changed

22.06 is Revision 4 Amendment 3 of the same UN regulation, and it replaced 22.05 with a wider test programme: more impact points, a broader spread of test speeds, and angled and kerb-shaped anvils rather than flat ones alone. Both are still legal in WA within the dates above. If you're buying new and you plan to keep this helmet for years, buy to 22.06.

Legal is a pass mark, not a score

Here's what that sticker doesn't tell you.

CRASH, the Consumer Rating and Assessment of Safety Helmets, is run by a consortium of government agencies together with the Australian Motorcycle Council. It rates helmets out of five stars for protection, and separately for comfort, which takes in noise, ventilation, field of view and fogging. Around 30 helmets are added each year and the ratings are published on the MotoCAP site.

Two helmets sitting on the same shelf, both perfectly legal, can be a long way apart on that scale. Ten minutes before you commit is a good trade.

MotoCAP does the same job for jackets, pants and gloves. It doesn't rate helmets.

Eye protection

No visor on your helmet? WA wants glasses or goggles that comply with AS/NZS 1698 or ECE 22 as amended. Clear lenses once the sun's down, and yes, that means carrying a second lens if you're riding home late.

Dirt, Road or Both? How Helmet Fit Changes for Motocross, Street and Adventure Riding

The fit tests don't change. What changes is the shape you're fitting and the job you're asking it to do. These are three different tools, and using one where another belongs is uncomfortable at best.

Motocross. Long peak, wide open eye port, no visor, extended chin bar, heavy venting. It's built around goggles and around riding slowly through hot air with your heart rate up, and at that job it's excellent. Put it on the highway and the peak catches wind and pulls at your head, while the open port hands you every decibel and every bit of grit going. The eye port is also the fit check people forget: try the helmet on with your own goggles, because the goggle has to seat in the port without gapping at the nose or shoving the helmet up your forehead.

Road. Full face, sealed visor, aerodynamic, quieter, warmer, less venting. Built for sustained speed and very good at it. Less happy on slow technical trail work, where there's almost no airflow and goggles won't seal against a visor. Fit matters differently here too, because a road helmet that's a touch loose will lift and buffet at 100km/h in a way it never does standing in the shop.

Adventure. A real compromise rather than a marketing one. Peak plus visor, usually with both removable, so you can run goggles on gravel and a sealed visor on the bitumen. More venting than a road helmet, more aerodynamic than an MX lid. If your riding splits between dirt and tar, this is the category built for you.

Pick the style around where and how you ride, not around what looks best on the shelf. Motocross helmets prioritise ventilation and goggles, road helmets prioritise a sealed visor and aerodynamics, adventure helmets borrow from both. Whichever way you go, check the approval label and run the same four fit tests.

What's on our shelves, by use case

Helmet brands in stock and on the site as at September 2026:

• Motocross and off-road: Leatt right across the range, from the 2.5 entry helmet up to the 9.5 carbon, plus Airoh and KTM. Shop adult and motocross helmets
• Road and adventure: Shoei, HJC, LS2 including the MX701 Explorer Carbon, Airoh, and Leatt's ADV range. Shop road and adventure helmets
• Junior: Leatt junior and LS2 junior off-road. Shop kids' helmets
• Women's: shop women's helmets

Stock moves. If you can't see the model you're after, call us on 08 9921 6888 and we'll tell you what's actually in the building.

Fitting a Kids' Motorcycle Helmet: The One They'll Actually Keep On

Measure a child's head exactly the way you'd measure your own, then buy the size that fits today.

We know why the other instinct exists. Kids grow, helmets aren't cheap, and buying one big to grow into feels like the sensible parenting move. It isn't. A helmet that's too big won't hold position on a smaller head, and every check below will fail on it. You're not buying a school jumper.

Junior helmets are sized on the same centimetre measurement and usually labelled YS, YM and YL. The steps between junior sizes are smaller than between adult sizes, so the measurement matters more, not less. Leatt's junior helmets run M at 51 to 52cm and L at 53 to 54cm, for example. Check the chart for whichever brand you're buying.

What to check on a kid's helmet:

• Weight. A junior neck is carrying it all day. A lighter shell means less fatigue and considerably less argument at the end of a session.
• The roll-off test, done by you. Kids will tell you anything fits, especially if the graphics are good.
• Cheek pads in contact. Same rule as adults. Firm, not painful.
• Goggles that suit the eye port. Buy them together where you can. Junior goggle and helmet combinations are not universal.
• Re-measure every season. A helmet that fitted last summer may not fit now.

And a bicycle helmet is not a motorcycle helmet. No chin bar, not built for the same impacts, and it carries none of the four standards approved in WA. They can look close enough on a shelf to be confusing, so read the label.

Junior gear: kids' helmets, kids' goggles, kids' protective.

How to Choose a Helmet for Hot WA Riding

Geraldton in February asks something different of a helmet than a city commute does, and so do the distances between towns out here. Four things worth weighing.

Ventilation isn't a nice-to-have. Look for real intake and exhaust vents you can open and close with a glove on, not moulded slots that are there for the photograph. Off-road at low speed there's barely any airflow at all, which is exactly where a properly vented helmet earns its money back.

A light-coloured helmet is easier to see. That's the WA Road Safety Commission's own advice, day and night.

Look after the liner. A removable, washable liner is worth having in this climate, for reasons anyone who has taken a helmet off after a long February ride will understand. Clean it the way the manufacturer tells you to, and replace the comfort padding when they say to rather than when it starts to look tired.

Plan for the distance between towns. A stop out here is a hot one. A hydration system and a spare clear lens for dawn and dusk aren't luxuries, they're the difference between a good day and a long one.

For dust, a good goggle seal does more for your eyes than any helmet feature will. Carry a spare lens or tear-offs on a long day. Shop goggles.

One Crash, One Liner: When Should You Replace a Motorcycle Helmet?

Replace a helmet after a crash, or after any impact while it's being worn. No inspection, no debate, no "it looks fine".

The reason is the bit you can't see. The energy-absorbing liner is built to crush once, and as the Snell Memorial Foundation puts it, even good helmets cannot provide adequate protection the second time. The shell can look showroom-new over a liner that has already done its only job.

The WA Road Safety Commission also advises replacing a helmet after a drop. Snell draws a distinction between an ordinary empty drop, off the seat, the bars or your hand, and an impact with a head inside, but recommends replacement or professional inspection wherever damage is suspected. Follow the helmet manufacturer's instructions for the specific incident.

Otherwise, replace it when any of these is true.

• It's done about five years of use. Snell recommends replacement after five years of normal use, because wear breaks down the pads and the liner. An unused helmet stored properly doesn't automatically expire at the five-year mark, so follow the manufacturer's guidance and inspect the condition too. The date stamp is under the comfort liner or on the strap.
• It's gone loose. Comfort pads and liner foam pack out with use, and a well-worn helmet can behave like one or two sizes larger than it did new. This happens slowly enough that you won't notice it happening. Re-run the roll-off test once a year.
• The strap, buckle or shell is damaged. Any crack, any frayed strap, any buckle that doesn't hold. No repairs, ever.
• It's been stored badly. A helmet that's spent summers in a hot car or hanging off a mirror in the sun has had a much harder life than its age suggests.
• Solvents have touched it. Petrol, thinners and harsh cleaners attack both the shell and the liner. Warm water and a helmet-safe cleaner, nothing else.

Can You Exchange a Helmet if the Size Is Wrong? The Bit We'd Rather Tell You First

No, and we'd rather you heard that from us now than from a returns page later.

Under our store policy, Sun City Motorcycles doesn't accept wrong-size or change-of-mind returns on helmets, goggles, socks, hats or any face covering, because they're hygiene-sensitive items. This does not limit any remedy available to you where goods fail an Australian consumer guarantee.

So getting the size right before you order matters more here than it does on a pair of gloves.

The WA Road Safety Commission's own advice is to try a helmet on for size before you buy, and not to buy online unless you're certain of the fit. We agree with them, which is an odd thing for an online retailer to put in writing, and we'd still rather say it than sell you the wrong size once.

Three ways to get it right:

• Come in. Bring your goggles if you've got them. We'll measure you and put you in a few shells so you can feel the difference between brands rather than read about it.
• Call us on 08 9921 6888 with your measurement and the bike you ride. We'll tell you which brands run wide, which run narrow, and what we'd put you in.
• Reorder the same model and size. If a helmet has fitted you for years, ordering it again takes most of the uncertainty out, but check that the shell, the interior and the size chart haven't changed since you bought the last one. Manufacturers redesign quietly.

Free shipping on orders over $99 Australia-wide.*

\Excludes Far North WA, NT, Far North QLD, TAS and non-metro or remote areas.*

Come and get fitted in Geraldton

Measuring a head takes two minutes. Getting the shape right takes a few helmets and someone watching how they sit, which is the part a size chart can't do for you.

We've been fitting helmets in Geraldton for over 20 years. Come in, tell us what you actually ride, and we'll put you in a few shells so you can feel the difference for yourself.

Sun City Motorcycles, 1/69 Flores Road, Webberton (Geraldton) WA 6530. Phone 08 9921 6888.

SHOP HELMETS CONTACT THE TEAM

Sources, for the page footer

• Road Traffic Code (Protective Helmets) Notice 2021 (WA), made under the Road Traffic Code 2000 reg 244, gazetted 16 July 2021: https://www.legislation.wa.gov.au/legislation/prod/gazettestore.nsf/FileURL/gg2021_126.pdf/$FILE/Gg2021_126.pdf?OpenElement=
• Road Safety Commission, Government of Western Australia, "Motorcycles, Helmets and Gear": https://www.wa.gov.au/organisation/road-safety-commission/motorcycles-helmets-and-gear
• Snell Memorial Foundation FAQ: https://smf.org/faq
• CRASH helmet ratings, published via MotoCAP: https://www.motocap.com.au/about-crash
• NSW Government, "New helmet safety data helps motorcyclists choose the safest option" (source for the number of helmets CRASH adds each year): https://www.nsw.gov.au/ministerial-releases/new-helmet-safety-data-helps-motorcyclists-choose-safest-option
• ACCC, consumer rights and guarantees: https://www.accc.gov.au/consumers/buying-products-and-services/consumer-rights-and-guarantees
• Manufacturer size charts, linked per model rather than generically. Adult Leatt sizes: https://us.leatt.com/products/moto-2-5-helmet Junior Leatt sizes: https://us.leatt.com/products/moto-3-5-junior-helmet-kit