12 vs 14 inch bike
12 inch is often a first balance or pedal bike. 14 inch adds a little room when the child has outgrown the lowest 12 inch saddle.
Wheel size and growth room
Kids Bike Size Chart
Kids bikes are sized by wheel diameter, not frame centimeters. Use the child's height to shortlist a wheel, read age as a clue only, then confirm with inseam and confidence that the child can start, stop, and steer today.
- Wheel sizes
- 12"–26" · 7 sizes
- Rider height
- 2'11"–5'3"
- Height (cm)
- 90–160 cm
- Inseam check
- 35–74 cm
Kids bike size chart
Shared wheel-size starting points. Confirm lowest saddle height and brake reach on the exact bike. Age is a secondary clue.
Wheel
Height
Inseam
Typical age
12" wheel
90–105 cm / 2'11"–3'5"
35–42 cm
2–4 years
14" wheel
95–110 cm / 3'1"–3'7"
38–46 cm
3–5 years
16" wheel
100–115 cm / 3'3"–3'9"
42–52 cm
4–6 years
18" wheel
107–130 cm / 3'6"–4'3"
46–56 cm
5–7 years
20" wheel
115–135 cm / 3'9"–4'5"
50–60 cm
6–9 years
24" wheel
130–150 cm / 4'3"–4'11"
58–68 cm
8–12 years
26" wheel
145–160 cm / 4'9"–5'3"
66–74 cm
11+ years
Wheel
12" wheel
Height
90–105 cm / 2'11"–3'5"
Inseam: 35–42 cm
Typical age: 2–4 years
Wheel
14" wheel
Height
95–110 cm / 3'1"–3'7"
Inseam: 38–46 cm
Typical age: 3–5 years
Wheel
16" wheel
Height
100–115 cm / 3'3"–3'9"
Inseam: 42–52 cm
Typical age: 4–6 years
Wheel
18" wheel
Height
107–130 cm / 3'6"–4'3"
Inseam: 46–56 cm
Typical age: 5–7 years
Wheel
20" wheel
Height
115–135 cm / 3'9"–4'5"
Inseam: 50–60 cm
Typical age: 6–9 years
Wheel
24" wheel
Height
130–150 cm / 4'3"–4'11"
Inseam: 58–68 cm
Typical age: 8–12 years
Wheel
26" wheel
Height
145–160 cm / 4'9"–5'3"
Inseam: 66–74 cm
Typical age: 11+ years
Use the child's height for the wheel size, then inseam and lowest saddle height.How to measure
Between sizes
Between two kids wheel sizes
16 vs 18 inch bike
16 inch covers many early pedal riders. 18 inch sits in the overlap before 20 inch. Confirm lowest saddle height before skipping 16.
18 vs 20 inch bike
18 inch is the closer match for a beginner in this overlap. Compare 20 inch when the child can start, stop, and reach the brakes on the larger bike today.
20 vs 24 inch bike
24 inch is a youth jump, not extra growth room on a 20 inch bike. The child should start, stop, and reach the brakes on the 24 inch bike today.
24 vs 26 inch bike
26 inch overlaps youth and adult XS. Use control and reach, not age, before moving into an adult frame chart.
Kids helmet and bikes
Helmet, three wheel-size bikes, and a bottle. Match the wheel size first, then confirm saddle height and brake reach.
Giro
Scamp MIPS II
Kids helmet with MIPS and a one-handed fit dial.
XS–S, typically 45–53 cm
View on AmazonPrice and availability on Amazon
Strider
12 Sport balance bike
No-pedal 12-inch bike for learning balance before a pedal bike.
Inseam 12–18 in
View on AmazonPrice and availability on Amazon
Retrospec
Koda Plus 16
Lightweight aluminum 16-inch kids bike with reach-adjustable brakes.
Inseam about 18–22 in, typically ages 4–6
View on AmazonPrice and availability on Amazon
Retrospec
Koda Plus 20
Aluminum 20-inch kids bike with EasySafe V-brakes.
Inseam about 22–25 in, typically ages 6–8
View on AmazonPrice and availability on Amazon
CamelBak
Podium Chill 21 oz
Insulated squeeze bottle for everyday rides.
Fits a standard ~73 mm cage
View on AmazonPrice and availability on Amazon
As an Amazon Associate we earn from qualifying purchases. Affiliate disclosure.
Kids sizing notes
Control now beats room to grow.
A kids bike is sized by wheel, then by saddle height and brakes. Height and age narrow the choice; they do not decide it.
Take your own measurements5 checks
The number is the wheel, not the frame
A 20 inch kids bike has 20 inch wheels — there is no frame centimeter to translate. Between two wheel sizes, the bike either fits the child today or it does not.
Check: Read the number as wheel diameter before anything else.
Height shortlists, inseam confirms
Height points to a wheel size. Inseam, lowest saddle height, and brake reach decide whether that bike is safe to start, stop, and steer.
Check: Confirm the child can sit on the saddle and still reach the ground.
Age is a filter, not a size
Age narrows the wheel band before you measure the child. Growth rates vary, so two children of the same age can need different wheels. Measure height and inseam first, then use age only to break a tie.
Check: Measure the child, then read the age column.
Buy for control, not for growth
A little room to grow is fine. A bike that is clearly too large is harder to start, stop, and turn, and it slows learning instead of extending the bike's life.
Check: If the child cannot reach the ground from the saddle, size down.
Saddle height and brake reach
The real fit test is whether the saddle drops low enough for the child's inseam and whether the brake levers reach a normal grip without shifting off the saddle.
Check: Brake levers should be reachable from a normal grip, not fingertips.
Related guides
Choose the right chart for your bike
Once you have a starting size, compare the chart for your bike type or exact model.
Kids bike calculator
Enter the child's height and inseam for a wheel size.
Beginners
Sizing advice for first-time riders.
By height
Compare adult and youth size ranges.
Woom size chart
Kids bikes sized by height and inseam.
How to choose a bike size
Use this guide when a young rider is moving into an adult-size frame.
Questions
FAQ
Quick answers to common bike-sizing questions.
What size bike does my child need?
Start with height and wheel size, then check inseam, saddle height, and brake reach. Age charts are only a clue.
What size kids bike does my child need by height?
Height sets the wheel band. A 16 inch bike covers 100–115 cm / 3'3"–3'9"; a 20 inch bike covers 115–135 cm / 3'9"–4'5"; a 24 inch bike covers 130–150 cm / 4'3"–4'11". Confirm inseam and saddle height on the exact bike.
What age is a 20 inch bike for?
A 20 inch bike fits about 6–9 years old, but height, inseam, saddle height, and brake reach decide. Age bands overlap.
What age is a 24 inch bike for?
A 24 inch bike fits about 8–12 years old. Check height, inseam, saddle height, and confidence before moving up.
What bike size does a teenager need?
A rider who has outgrown the 26 inch bike moves into adult XS or S frames. Compare reach and control before buying growth room.
Is a child bike size chart by height better than age?
Height is usually more accurate than age, but inseam and bike control still decide the final size.
Should I buy a kids bike with growth room?
Yes, but not so much that starting, stopping, or steering becomes difficult.
Is a 16 inch bike the same as a 16 inch frame?
No. Kids bikes are sold by wheel diameter. Frame size in centimeters is an adult road and gravel convention.
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