What Size Bike Does My Child Need? – Kids Bike Size Guide by Age & Height
Choosing the right size bike for your child is key to building confidence, comfort, and safety when learning to ride. From balance bikes for toddlers to trail-ready mountain bikes for older kids, finding the perfect fit makes all the difference. Use our kids bike size guide to help you match wheel size to your child’s age and height—before you buy.
How Are Kids’ Bikes Sized?
Unlike adult bikes, which are sized by frame dimensions, children’s bikes are sized by wheel diameter. The most common sizes include 12”, 14”, 16”, 20”, 24”, 26” and 27.5” wheels, each suited to a specific age and height range.
Use the chart below as a quick reference to find the best fit for your child.
Kids Bike Size Chart – Age & Height Guide
| Rider Height |
Age Range |
Recommended Wheel Size |
| 86 – 102cm |
2 – 4 years |
Balance Bikes / 12″ |
| 99 – 117cm |
3 – 6 years |
14″ and 16″ |
| 114 – 132cm |
5 – 8 years |
20″ |
| 127 – 150cm |
7 – 10 years |
24″ |
| 146 – 170cm |
10+ years |
26″ and 27.5″ |
Balance Bikes & 12” Wheels (Age 2–4)
For toddlers and first-time riders, balance bikes are the perfect introduction to cycling. These pedal-free bikes focus on developing key skills like balance and steering, giving your little one the confidence to ride solo.
14” & 16” Wheel Bikes (Age 3–6)
Once your child masters a balance bike, it’s time for their first pedal bike. Bikes in this category are simple and sturdy, usually single-speed with easy-to-use brakes—ideal for riding on pavements, park paths and light trails.
- Ideal for: Ages 3–6 or heights of 99–117cm
- Introduces pedals and brakes
- Lightweight, durable frames
- Suitable for both tarmac and light off-road use
- Recommended models: Frog 38 (14”) and Frog 44 (16”)
20” Wheel Bikes (Age 5–8)
As your child’s confidence and strength grow, 20” wheel bikes offer more range and control. Often equipped with gears and front suspension, they’re perfect for exploring rougher terrain and longer rides.
- Ideal for: Ages 5–8 or heights of 114–132cm
- Introduces gears for varied terrain
- Optional front suspension for comfort
- Perfect for off-road trails and park riding
- Top picks: Cube Acid 200 Disc, Merida Matts J.20
24” Wheel Bikes (Age 7–10)
With 24” wheels, bikes begin to closely resemble smaller versions of adult bikes. Built for pre-teens, these bikes cater to specific riding styles, whether it’s commuting, trail riding or leisure cycling.
- Ideal for: Ages 7–10 or heights of 127–150cm
- Gearing suited for hills and mixed terrain
- Suspension forks and wider tyres on MTB models
- Rigid forks and hybrid geometry for pavement and paths
- Recommended: Cannondale Kids Quick 24, Cube Acid 240 Disc
26” & 27.5” Wheel Bikes (Age 10+)
For older children and young teens, 26” and 27.5” wheel bikes offer a near full-size riding experience with youth-specific geometry. These bikes support longer rides, more aggressive terrain and specialised disciplines like road cycling or mountain biking.
- Ideal for: Ages 10+ or heights of 146–170cm
- Scaled-down adult features and components
- Suspension forks and wide gearing on MTBs
- Drop bars and compact cranks on junior road bikes
- Top models: Cube Nuroad Rookie (road), Whyte Secta 26 (MTB), Trek Marlin (26″ & 27.5″)
Final Thoughts – Finding the Right Size Bike for Your Child
The right size bike ensures your child can ride confidently and safely, whether they’re just learning or tackling forest trails. Always measure height and consult a size chart before buying. If your child is between sizes, consider their experience level—beginners benefit from a smaller, easier-to-handle bike.
Wheelbase have 3 stores across the north of England where you can try Childrens bikes for size. If you order a childrens bike online at Wheelbase, it will arrive ready to ride, having been built and inspected by our Cytech Mechanics. On larger bikes you may need to add the front wheel.
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