Children's bikes are typically sized by their wheel size - unlike adults where the frame size is measured from bottom bracket to top of seat tube...which often then gets translated to a vague XS/S/M/L/XL category.
Article written by me, Craig, no Microsoft Copilot or other AI involvement
However, due to the designs of each bike from every manufacturer - you're often left guessing.
For sizing a child's bike it's relative straight forward with a simple rule
"The child should be able to stand with both feet on the ground over the lowest point on the top tube (the tube that runs between saddle and handle bars)"
Craig, Holbrook Cycleworks
12" Charger / BigFoot
Stand-over heights:
- Charger - 33cm
- Big Foot - 33cm
Typically the 12" balance bike will suit a child from 20 months to 4 years.
Balance bikes develop the coordination and balance skills that mean the 'hard' part of riding a bike is dealt with before reaching pedals.
14" Belter / Seeker
Stand-over heights:
- Belter 14" - 37cm
- Seeker 14" - 37cm
Typically the 14" bike will suit a child aged 3 - 5 years. Although there are children that have been known to learn to pedal aged TWO !!
The first entry in a pedal bike is very exciting - geometry and weight are massive factors in keeping that excitement and interest level up.
- Belter - 5.48Kg
- Seeker - 6.02Kg
Weight is important for any parent too - we've all had to carry a bike home when a child gets bored / tired / fed-up or interested in something else!
16" Belter / Seeker
Stand-over heights:
- Belter 16" - 41cm
- Seeker 16" - 41cm
Typically the 16" bike will suit a child aged 3 - 6 years.
- Belter - 5.75Kg
- Seeker - 6.34Kg
The Charger range appears from 16" upwards but we'll talk about those separately.
20" Belter / Seeker
Stand-over heights:
- Belter 20" - 50cm
- Seeker 20" - 51cm
Typically the 20" bike will suit a child aged 6 - 8 years.
- Belter - 7.77Kg
- Seeker - 8.79Kg
The Charger range appears from 16" upwards, with the Helion introduced at 20", we'll talk about those separately.
24" Belter / Seeker
- Belter 24" - 58.5cm
- Seeker 24" - 60cm
Typically the 24" bike will suit a child aged 8 - 11 years.
- Belter - 10.2Kg
- Seeker - 10.32Kg
The Charger and Helion ranges will be discussed separately.
Final words...
Sizing a bike, whilst simple - can feel quite daunting when buying online.
Use the manufacturer website (no matter who it is) to get as much geometry information as possible, stand over heigh should easily be available.
If in doubt, contact your local bike shop, and don't forget to buy through them too.
You should be able to try various sizes of bikes, but don't be disappointed if the range isn't massive - bike shops can't always carry huge volumes of stock.
You can, at least, have an informed conversation with a real person - this goes a long way when it comes to a considered purchase, like buying a bike.
Your bike should come assembled and checked - to manufacturer specifications. Most shops will offer a tune-up after so many miles, or weeks, to make sure everything is working as it should - and safely!