Helmet sizing
Helmet size for a 9 year old
A typical 9 year old's head measures about 53 cm (20.9 in) around, which is usually a S helmet. Measure 1 in above the eyebrows and buy a CPSC-certified helmet whose own fit range covers the number; for the skatepark choose one also certified to ASTM F1492.
At 9, kids are usually riding electric scooters around 10 mph and more time at the skatepark. That decides the certification: CPSC is required on every US bike helmet, and for skatepark riding a dual-certified helmet that also meets ASTM F1492 handles repeated smaller impacts.
Head size around age 9
| Age | Typical head | Usual size |
|---|---|---|
| 8 | 52.5 cm / 20.7 in | S |
| 9 | 53 cm / 20.9 in | S |
| 10 | 53.5 cm / 21.1 in | S |
Measure and convert
Helmet sizeUpdates as you type
Size S (53.0 cm / 20.9 in)
- Certification for this riding
- CPSC + ASTM F1492 (multi-impact)
- Fit check
- Two fingers above the eyebrows, straps in a V under the ears, one finger under the chin strap
- Helmets here whose stated fit covers 53 cm
- 8
Between sizes, choose the smaller one if its range covers you and tune with the dial. Replace any helmet after a crash.
Helmets whose stated fit covers 53 cm
| Helmet | Price | Fit | Certification stated |
|---|---|---|---|
| Bell Rally Child Helmet | $18.99 | 52-56 cm | CPSC |
| Bell Rally Child Helmet | $18.99 | 52-56 cm | CPSC |
| MOUNTALK Kids Bike Helmet | $19.97 | 46-54 cm | CPSC |
| Bell Child Rally Bike Helmet | $22.99 | 52-56 cm | CPSC |
| DARME Kids Bike Helmet Set | $23.50 | 48-57 cm | check listing |
| WayEee Kids Bike Helmet Set Skateboard Knee Pads | $23.99 | 48-54 cm | check listing |
| WayEee Kids Bike Helmet Set Skateboard Knee Pads | $23.99 | 48-54 cm | check listing |
| Bimalsic Toddler Bike Helmet Adjustable Dial Fit -12 Vent for 2-6 Year | $23.99 | 45-54 cm | CPSC |
| BELL Marvel Spiderman Hero Helmet | $24.96 | 50-54 cm | CPSC |
| Bell Child Rally Helmet | $25.32 | 52-56 cm | CPSC |
| Odoland Kid's Bike Helmet Adjustable Fits 48-54cm | $27.05 | 48-54 cm | CPSC |
| Besttravel Kids Bike Helmet | $27.88 | 48-54 cm | check listing |
| TurboSke Skateboard BMX Multi-Sport Helmet for Youth | $28.99 | 52-61 cm | check listing |
| ZLEIOUY Color Gradient Adjustable Bike Helmet with Knee and Elbow Pads | $29.59 | 48-58 cm | check listing |
Helmets for a 9 year old, plus pads
Prices change often; the button shows today's price on Amazon.
Electric scooter for a 9 year old
Other ages
- Helmet size for a 1 year old
- Helmet size for a 2 year old
- Helmet size for a 3 year old
- Helmet size for a 4 year old
- Helmet size for a 5 year old
- Helmet size for a 6 year old
- Helmet size for a 7 year old
- Helmet size for a 8 year old
- Helmet size for a 10 year old
- Helmet size for a 11 year old
- Helmet size for a 12 year old
Questions riders ask
What size helmet does a 9 year old need?
Most 9 year olds measure about 53 cm around the head, a S in most brands, but heads vary by 2 to 3 cm either way at every age. Wrap a soft tape measure about 1 in above the eyebrows and over the widest part at the back, then choose the helmet whose stated fit range covers the number, ideally near the middle of it.
How should a kids helmet fit?
Two fingers of forehead above the eyebrows, side straps forming a V just under each ear, and no more than one finger under the buckled chin strap. Tighten the rear dial until the helmet does not move when the child shakes their head. If it rocks back to show the forehead, it is too big or the front straps are loose.
Does a 9 year old need a skate helmet or a bike helmet?
At 9, with electric scooters around 10 mph and more time at the skatepark, a dual-certified helmet is the better buy: CPSC for bike and scooter impacts plus ASTM F1492 for the repeated smaller falls of skatepark riding. It covers more of the back of the head too. A CPSC bike helmet is fine for riding on paths.
Wear a helmet every ride, and check your state and city rules on age, speed and where scooters may ride. This page is researched guidance, not professional, legal or medical advice. Specifications come from each product listing and can change; confirm on the listing before you buy.