Bike Sizing Guide – Kids’ Bikes

Kids bike sizing usually focuses on the wheel diameter of a bike, for example 14 inches, and links it to the age of a child, for example 3-5 years. Read our Kids Bike Sizing Guide below or download a .pdf here for your reference.



1. Kids bikes: Age and wheel size

Age can be a misleading measurement to use when buying a bike, so if you have any doubts at all we recommend that you contact us. Having said that, here’s a rough guide for starters.

Bike Size Wheel Size
2 – 4 years Balance Bike
3 – 5 years 14″-16″
4 – 7 years 16″
5 – 10 years 20″
8 – 14 years 24″
11+ 13″ – 14″ adult

Frog 522. How to measure a child for a Frog bike

Frog bikes use the child’s inside leg measurement, instead of wheel size, when talking about their kids bike sizes. For example, a Frog 43 is designed for a child with a minimum inside leg measurement of 43cm, usually aged 3-4 years old. See Frog bike sizing chart…

3. What to look for in a kids bike

When choosing a child’s bike, these are the things to be aware of:

  • You want a bike with plenty top tube (crossbar) clearance so they can safely hop off the saddle.
  • You want a bike that’s easy for a child to manage. A bike that’s too long is unwieldy, harder to control and harder to steer. A bike with 12″ wheels will not only be shorter in height than a 16″ wheeler, it will also be shorter in length.
  • Again, you want a bike that’s easy to manage. Heavy bikes are hard for younger riders just building their strength. This is worth remembering when choosing between one of our 12 kilo junior mountain bikes against a 25 kilo full suspension supermarket special. Read: Kids hate cheap bikes and here’s why
  • You want a bike that will last as long as possible: Small enough to straddle, yet big enough to offer years of growth, and well built enough to pass on to a wee brother or cousin in years to come. The kid’s bikes we offer are all from well-respected, quality brands.

4. Kids bikes sizes and what they look like

Balance bikes for 2 – 4 years olds

frog tadpole bike

No pedals, no cranks and no brakes enable the young rider to learn how to balance and steer with minimum distraction.

See all balance bikes


14-16 inch-wheeled bikes for 4 – 7 years olds

frog 16 inch kids bike

Single-speed and with or without stabilisers: it’s on a 14″ or 16″ wheeler that the child often graduates from play/pavement bike mode to serious adventures such as rides through the park and pedalling to school.

See all 14-16-inch wheelers


20 inch-wheeled bikes for 5 – 10 years olds

Frog 20 inch kids bike

Now we’re getting serious. 20-inch wheeled bikes feature 5 or 6 gears to smooth the climbs and the MTBs (mountain bikes) boast suspension forks to smooth the bumps.

See all 20-inch wheelers


24 inch-wheeled bikes 8 – 14 years olds

frog bike in greenWith or without suspension; triple chainset transmission with 15 / 18 / 21 / 24-speed gears so kids can crank it up a notch.

See all 24-inch wheelers


26 inch-wheeled bikes 11+

Whyte 405 2017 kids mountain bike

A 26″ wheeler is of course an adult-sized bike. Some adult bikes are available in very small sizes. For instance, you can get a Specialized Hardrock with a 13″ frame which kids as young as 11 can manage. The obvious advantage with this size is the much wider choice of spare parts (the number of 26″ tyres on the market outnumbers 24″ tyres at least 100 to 1). Another advantage is that spare tubes, for instance, can be pooled on family rides.

See all 26-inch wheelers


Need to know more?

Phone 0345 257 0808 for free or email enquiries@edinburghbicycle.com to speak to someone in our online team who can give you helpful advice about buying a kids’ bike. They’ll be able to provide more tailored information based on your child’s height and age.

Shop Kids Bikes

Check out our range of children’s cycling clothing and helmets