Guide to Kid Bike Sizes : Children's bike sizes are determined by wheel diameter, not seat height and frame size. The chart below should help you narrow your search, but it is not a substitute for an expert helping you find a bike that is most suitable. After kids outgrow children's bikes they'll move into small-framed adult bikes with 26 - 28 inch wheels, which are sized by the length of the stube.

Click any picture for bicycles in that category

Approximate AgeWheel diameterChild's InseamComments:
2-4 years12 inches14-17 inchesMost come with training heels, some are direct drive
5-8 years16 inches18-22 inchesMost have rear coaster breaks and pneumatic tires, some have front hand brakes.
7-10 years20 inches22-25 inchesSome models are multi-speed with hand brakes.
9+ years

24 inches

26 inches

24-28 inchesCan have most of the feature of adult bike

Beach Cruisers

Beach cruisers are designed for those who like the classic bicycle styles of the 1950s. They have 26-inch wheels and wide (2 inches) whitewall tires. For comfort, they have wide seats and upright handlebars. In the 1950s, bicycles like these came with 1 or 3 gears. Today they come with 1 or 7 speeds.

Mountain Bicycles
In the 1980s mountain bicycles revolutionized the bicycling industry. No longer were cyclists restricted to riding on roads. Mountain bicycles have to be rugged to stand up to off-road riding. They have wider (approximately 2 inch), knobby tires. Wheels are slightly smaller (26 inch) than on road bicycles. Mountain bicycles have at least 21 gears, and they include lower gears than would be found on a road bicycle, due to the increased resistance from off-road riding. Many models have shocks on the front and/or rear to reduce the shocks that riders will feel when going over obstacles on off-road trails. The handlebars on mountain bicycles allow the rider to remain in a more upright position than the drop handlebars of road bicycles, making it easier to see obstacles (like tree roots) on the trail.

Road Bicycles

In the 1970s all bicycles were road bicycles. They are distinguished by narrow tires (approximately 1 inch), usually 700 centimeter (approximately 27 inch) wheels, and drop handlebars. They are intended for use on paved roads or trails. The narrow tires reduce rolling friction, and the drop handlebars put the rider in a position that minimizes air resistance. The frames are strong but lightweight. Most have at least 21 speeds (3 sprockets front, 7 rear).