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 |
0.5 – 2 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 |
9+ years |
26″ and 27.5″ |
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”) | Woom GO 2 (14″) and Woom GO 3 (16″)
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.
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.
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 9+ 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″), Woom Explore 6 (26″)
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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Hottest Kids’ Bikes This Christmas
With Christmas just around the corner, finding the perfect bike is at the top of many parents’ wish lists. Whether it’s a first children’s bike with stabilisers or a capable junior mountain bike, choosing the right size and style is key to building confidence and excitement. This year’s best kids’ bikes combine lightweight frames, reliable components and child-specific designs to make every ride fun, safe and easy to handle.
All kids’ bikes from Wheelbase are fully assembled and safety checked by expert mechanics, then delivered ready to ride with only minor assembly required, or can be collected from our stores in Staveley, Ilkley and Darlington — making Christmas morning that little bit more magical.
- 6061 aluminium SCR frame with adjustable geometry and ISCG guide mounts
- 140mm RockShox Pike front suspension and 135mm RockShox Deluxe Select+ rear shock
- Shimano Deore 11-speed drivetrain (32T chainring, 11–51T cassette)
- KS 900I dropper seatpost with size-specific drop
- WTB ST i30 tubeless-ready rims and Maxxis Minion DHF / Dissector tyres
- TRP Slate Evo 4-piston hydraulic disc brakes with 180mm rotors
- 27.5-inch wheels for smooth, fast rolling and improved control
- Alpha Silver aluminium frame with rack & kickstand mounts
- SR Suntour XCT 30 suspension fork (80–100 mm travel)
- Shimano CUES 9-speed drivetrain
- Bontrager Montrose tyres (27.5″ or 29″)
- Shimano MT200 hydraulic disc brakes
- Internal cable routing & dropper post compatibility
- Superlight 9.5 kg aluminium frame with child-specific geometry
- 26″ wheels with ultralight rims & sealed hubs
- 8-speed microSHIFT drivetrain (11–34T range)
- Hydraulic Promax disc brakes
- Schwalbe Billy Bonkers 26×2.0″ folding tyres
- Ergonomic Selle Royal saddle, slim grips & adjustable stem
- Lightweight 6061 T6 aluminium frame with internally routed cables and dropper post compatibility
- SR Suntour XCR air fork with 100mm travel, adjustable rebound, and lockout
- 26″ wheels paired with Vee Tire Co. Crown Gem 2.25” tyres for versatile trail grip
- Shimano 1×9 drivetrain with 30T narrow-wide chainring and 11-36T cassette
- Tektro HD-M275 hydraulic disc brakes with 160mm rotors front and rear
- Size-specific youth components including short cranks, junior saddle, and lock-on grips
Why choose these bikes?
Perfect for confident young riders aged 10+, these bikes bridge the gap to adult bikes. The Trek Marlin 5 Gen 3 is versatile enough for commuting and trail riding. The Woom Explore 6 stands out for its ultra-lightweight design, making climbs easier and long rides more comfortable. The Whyte T-140 is a market leading option for a smaller full suspension bike.
- Lightweight 6061 T6 aluminium frame & carbon fork
- 24″ tubeless-ready wheels with sealed bearings
- 9-speed SRAM X5 gearing
- Hydraulic disc brakes with child-specific levers
- Schwalbe Rocket Ron 24×2.35″ tyres
- Wide bars & ergonomic saddle for control and comfort
- Lightweight TFS 6061 aluminium frame
- 24×2.4″ wide tyres for grip & cushioning
- Rigid fork keeps weight down (approx. 10 kg overall)
- Microshift Acolyte 1×8 drivetrain
- Tektro hydraulic disc brakes with short-reach levers
- Flip-flop stem and spacers for growth adjustability
-
Aluminium Lite 6061 frame – lightweight and durable
-
SR Suntour XCT JR fork with 60mm travel for trail comfort
-
Shimano BR-MT200 hydraulic disc brakes for confident stopping
-
8-speed Shimano drivetrain (RD-M3020 with Rapidfire-Plus shifters)
-
24″ Cube DB29 wheels for nimble handling
-
Junior-specific finishing kit including 127mm crankset and 580mm bars
Why choose these bikes?
Both models are trail-ready and confidence-inspiring. The Woom OFF 5 prioritises performance with a carbon fork and ultra-light frame, while the Merida Matts J.24+ adds extra stability with its wide plus-size tyres and simple 1x gearing, ideal for developing skills.
Merida Matts.J 20
• Lightweight TFS 6061 aluminium frame with rigid fork for responsive handling
• Wide 2.4″ tyres for extra grip, stability, and comfort
• 1×8-speed drivetrain with Microshift trigger shifters for simple gear changes
• Tektro hydraulic disc brakes with short-reach levers for powerful stopping
• Flip-flop stem and adjustable spacers to accommodate growing riders
- Lightweight 8.15 kg frame
- Tektro brakes with small levers
- 8-speed FrogFitTechnology® shifters
- Low bottom bracket for stability
- Adjustable handlebar height & quick-release seatpost
- Designed and built in Great Britain
- Lightweight AA 6061 aluminium frame
- 20″ wheels, suitable for riders 115–130 cm
- 7-speed Shimano gearing with twist shifter
- Hydraulic Promax disc brakes
- Schwalbe Billy Bonkers tyres with reflective sidewalls
- Weight: 7.8 kg
Why choose these bikes?
Ideal for children transitioning to geared bikes, these 20″ options blend lightweight handling with reliable performance. The Cube Acid 200 Disc focuses on trail fun, the Frog 53 is a versatile hybrid for everyday rides, and the Woom Explore 4 balances off-road grip with on-road efficiency.
- Lightweight aluminium frame
- 16″ wheels with fast-rolling tyres
- Single-speed drivetrain with enclosed chain guard
- Junior-specific V-brakes with short-reach levers
- Includes stabilisers
- Fits riders approx. 92–109 cm
- Ultra-light 6.39 kg frame
- Tektro brakes with easy-reach levers
- Patented Frog cranks for efficient pedalling
- 16″ wheels, designed for 4–5-year-olds
- Adjustable handlebar and saddle height
- Lightweight AA 6061 aluminium frame
- 16″ Schwalbe Little Joe tyres with reflective sidewalls
- Steering limiter & mini V-brakes with colour-coded levers
- Wide BMX-style bars for control
- Quick-release seatpost for easy adjustment
- Suitable for 105–120 cm riders
Why choose these bikes?
These models give younger riders the best possible start. Lightweight frames and intuitive handling help build confidence, while proper brakes and geometry ensure safety as they learn to pedal independently.
- Lightweight but sturdy frame
- 12″ wheels with soft grips
- Easy Tektro rear brake with adjustable lever
- Steering limiter for safety
- Suitable from 2–3 years (min inside leg 32 cm)
- Superlight 3 kg aluminium frame
- Low entry point & long wheelbase for stability
- Schwalbe G-One Speed tyres with reflective sidewalls
- V-brake with colour-coded lever
- Wide ergonomic bars & slim grips
- Grows easily with adjustable saddle
Why choose these bikes?
Balance bikes are the perfect way to start cycling. They teach steering and balance naturally, making the jump to pedals seamless and stress-free.
Make This Christmas Magical
Wheelbase offers a full range of kids’ bikes and junior bikes in sizes from 12″ to 27.5″ wheels, all designed to inspire young riders and build confidence. Every bike is prepared by experts and can be delivered ready to ride with only minimal assembly, or collected from our stores in Staveley, Ilkley and Darlington.
With trusted brands like Trek, Cube, Woom, Merida and Frog, this year’s hottest kids’ bikes make unforgettable Christmas bike gifts that will keep children riding, exploring and smiling all year round.
