Kids Helmet Size Calculator Australia
Bike, ski and skate helmet sizes from head circumference — AS/NZS 2063 compliant.
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How to measure your child's head
Use a flexible tape measure. Wrap it around the widest part of the head — about 2 cm above the eyebrows, above the ears, and around the back.
Take 2–3 measurements and enter the largest. No tape measure? Use a piece of string and measure it against a ruler.
Please enter a head circumference between 40 cm and 68 cm.
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Recommended size
M
55–58 cm
💡 Sizes vary between helmet brands and models. Always try the helmet on and perform the fit checks below before purchasing. A correctly sized helmet should not wobble or tip when you push it.
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About this Australian helmet size calculator
Helmet sizing in Australia is based on head circumference in centimetres. Bike helmets sold in Australia must comply with AS/NZS 2063:2008, the Australian and New Zealand standard for bicycle helmets — look for the compliance mark on any helmet you buy. Ski and snowboard helmets are not mandatory under Australian law but are strongly recommended; most helmets sold at Australian ski retailers comply with EN 1077 (European standard for alpine ski and snowboard helmets). Skate and multi-sport helmets in Australia may carry AS/NZS 2063 multi-sport certification or CPSC 1203 (US Consumer Product Safety Commission standard), which is widely recognised in Australian skate parks.
Bike: AS/NZS 2063:2008 — mandatory in all Australian states
Ski: EN 1077 — recommended, commonly sold in AU
Skate: AS/NZS 2063 multi-sport or CPSC 1203
Full helmet size chart
| Size | Head Circ. (cm) | Approx. Age | Bike Helmet | Ski Helmet | Skate Helmet |
|---|---|---|---|---|---|
| XXS | 44–48 cm | 1–3 years | XS / Toddler | — | — |
| XS | 48–52 cm | 2–5 years | XS / Kids S | XS | XS / Youth S |
| S | 52–55 cm | 5–9 years | S | S | S / Youth M |
| M | 55–58 cm | 8–12 years | M | M | M |
| L | 58–62 cm | 12+ / Adult | L | L / Adult S–M | L |
| XL | 62–68 cm | Adult | XL / Adult L | XL / Adult L | XL / Adult |
How to check a helmet fits correctly
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Two-finger ruleThe helmet should sit 2 finger-widths above the eyebrows. Too low blocks vision; too high leaves the forehead unprotected.
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Push testPush the front back, then the back forward. It should move no more than 2 cm in any direction. If it tilts easily, try a smaller size.
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Chin strapFasten the strap. You should be able to fit one or two fingers between the strap and your child's chin. If they can open their mouth wide, the strap should pull snug.
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No wobbleAsk your child to shake their head side to side. The helmet should stay in place and not rock or spin. Adjust the retention dial (if present) until snug but comfortable.
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Frequently asked questions
Yes. Wearing an approved bicycle helmet is compulsory for all cyclists in all Australian states and territories, regardless of age. The helmet must comply with Australian Standard AS/NZS 2063 — look for the compliance mark on the inside. Penalties for not wearing a helmet vary by state but can be significant. Helmets that only meet overseas standards (US CPSC or European EN 1078) may not be legally compliant in Australia — always check for the AS/NZS 2063 marking when buying a bike helmet in Australia.
Replace a bike helmet after any significant impact, even if there is no visible damage — the foam liner compresses on impact and will not protect as well in a subsequent fall. Beyond that, most manufacturers recommend replacing helmets every 3–5 years as materials degrade over time, particularly with exposure to Australia's UV conditions. Always check for the manufacture date stamped inside the helmet. Replace sooner if the straps are frayed, buckles are cracked, the shell is damaged, or the retention system no longer fits snugly.
It depends on the helmet. Some helmets are certified as multi-sport and carry both cycling and skate/multi-sport certifications — these are suitable for both. However, a standard bike helmet (designed to protect against a single high-impact crash) is not necessarily suitable for skateboarding, which involves multiple lower-impact falls. Skate-specific helmets are designed to withstand repeated lower-energy impacts. Check the certification labels inside the helmet — a multi-sport or dual-certified helmet will explicitly list both uses.
There is currently no mandatory Australian standard specifically for ski or snowboard helmets. However, most Australian ski resorts strongly recommend or require helmets, and all reputable helmets sold in Australian ski shops comply with the European standard EN 1077 or ASTM F2040. When buying a ski helmet in Australia, look for the EN 1077 certification on the label. A properly fitted, certified ski helmet significantly reduces the risk of traumatic head injury on the slopes.
For most Australian 5-year-olds, a size S helmet (52–55 cm head circumference) is the most common fit — but head size varies significantly between children of the same age. Always measure your child's head circumference rather than buying by age. Use a flexible tape measure, wrap it around the widest point of the head about 2 cm above the eyebrows, and enter the measurement into the calculator above. Head size does not increase as quickly as body size, so a helmet bought to grow into is likely to be dangerously loose now.
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