A 10-year-old usually needs a 24-inch bike. The average height at this age is about 4 ft 6 in (138 cm), right in the middle of the 24" range (4 ft 2 in-4 ft 11 in / 127-150 cm). If they're taller than 4 ft 9 in (146 cm), they can move up to a 26" or 27.5" in size XS.
- Typical height
- 4′6″ 138 cm; range 4′2″–4′11″ (126–151 cm)
- Their bike
- 24" or 26" or 27.5" size xs
- Bike weight
- < 21.1 lb 9.6 kg: 30% of about 70 lb (32 kg)
Calculate with their exact height
How tall is a 10-year-old?
According to the World Health Organization (WHO), half of 10-year-old boys are taller than 54.3 in (137.8 cm) and half of girls are taller than 54.6 in (138.6 cm). Between the 3rd and 97th percentiles (94% of kids) the range is wide: from 4′2″ to 4′11″ (126-151 cm). In the US, the CDC growth charts give a median of 54.6 in (138.6 cm) for boys and 54.3 in (138.0 cm) for girls. That's why age is a guide, but height is what decides the bike: measure your child barefoot against a wall before you buy.
| 3rd percentile | Median | 97th percentile | |
|---|---|---|---|
| Boys | 49.5 in (125.8 cm) | 54.3 in (137.8 cm) | 59.0 in (149.8 cm) |
| Girls | 49.8 in (126.6 cm) | 54.6 in (138.6 cm) | 59.3 in (150.7 cm) |
What size bike they need
This is the age when the difference between kids who've hit their growth spurt and those who haven't shows the most. A 4 ft 2 in (126 cm) child can still ride a large 20"; a 4 ft 11 in (150 cm) child is already at the smallest adult bike size. Kids' 26" bikes fit from about 4 ft 7 in to 5 ft 5 in (140-165 cm) (Woom EXPLORE 6), and Islabikes makes a 27.5" for 4 ft 8 in (142 cm) and up.
| Size | Height | Inseam |
|---|---|---|
| 24-inch | 4′2″–4′11″ (127–150 cm) | 23–28 in (58–70 cm) |
| 26" or 27.5" size XS | 4′7″–5′5″ (140–165 cm) | 25–30 in (64–76 cm) |
How to check the fit
Leg almost straight with the pedal at the bottom and toes on the ground when seated. On bigger bikes, posture starts to matter: arms slightly bent, back leaning forward a little and neck relaxed. If they're stretched out to reach the handlebar, the bike is too long for them even if the seat height works.
Ideal bike weight
At 10, a child weighs about 70 lb (32 kg), and 30% is about 21 lb (9.5 kg). Light 24" bikes come in around 20 lb (9 kg) (Woom, without pedals) and high-end kids' 26" bikes at 21 lb (9.5 kg).
Brakes: coaster brake or hand brakes
Disc brakes, ideally hydraulic: they need less hand strength and work just as well in the rain. Woom's 24" and 26" bikes come with them. If the bike has V-brakes, check the pads often.
Gears
Between 8 and 10 gears with a single chainring. At this age they're already riding small climbs with the family: look for a big cog (36-42 teeth) so they don't have to get off and walk. Woom's 24" and 26" bikes have 8 gears; the Btwin 24", 6.
Training wheels or a balance bike
Training wheels are long gone. Now it's about independence: rides on rail trails, first road rides with an adult, learning to fix a flat. If they want to race, ask at your local cycling club or youth mountain bike team.
What to look for when you buy
- Size: almost certainly 24"; a 26" or 27.5" XS if they're taller than 4 ft 9 in (146 cm).
- Weight: under 22 lb (10 kg).
- Hydraulic disc brakes if they'll ride trails.
- Short cranks: adult ones (170 mm) force their knees up high.
- A quality kids' bike can be resold or handed down to a sibling: factor that into the price.
Frequently asked questions
What size bike for a 10-year-old?
24 inches in most cases. If they're taller than about 4 ft 9 in (146 cm), a 26" or 27.5" in size XS.
Can a 10-year-old ride an adult bike?
Only if they're taller than about 4 ft 11 in (150 cm) and it's a size XS or XXS. Even then, kids' 26" bikes are lighter and come with cranks and levers sized for them.
How tall is a 10-year-old?
The WHO median is 4 ft 6 in (138 cm), with 4 ft 2 in to 4 ft 11 in (126-150 cm) between the 3rd and 97th percentiles. The CDC growth charts put the US median at about 4 ft 6 in (138-139 cm).
Sources
- WHO: Height-for-age, boys 2 to 5 years (percentiles)
- WHO: Height-for-age, girls 2 to 5 years (percentiles)
- WHO: Height-for-age, boys 5 to 19 years (percentiles)
- WHO: Height-for-age, girls 5 to 19 years (percentiles)
- CDC: Growth charts data tables, stature-for-age, 2 to 20 years
- Woom: Compare woom bikes
- Islabikes: Size chart
- Trek: Precaliber kids’ bikes
- Decathlon: Btwin Original 100 20" manual
- Mercê C et al. (2022). Learning to Cycle: From Training Wheels to Balance Bike. IJERPH
- Two Wheeling Tots: Kids’ bike buying guide