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How to choose the right bike size


When choosing a bicycle, the size is one of the most important parameters. If cycling is your hobby and you want your offspring to start it in an early age, make sure to select the correct bike size, appropriate for the age and height of the child.

Children's bike sizes

Choosing the right size is particularly difficult when you are buying a bike for a child. Buy a bike too small or too large and the child will feel very uncomfortable; a particularly bad choice may even turn them off cycling for good. It’s tempting to buy a larger bike so your child can “grow into” it, but it’s a bad idea and can actually be dangerous. Make sure to buy a properly sized bike and swap it for larger models as your child grows. With children's bicycles, you can generally tell the size by looking at the bike wheel diameter.

Kids bike size chart

Child 2-4 yearsChild 3-5 yearsChild 4-6 yearsChild 5-8 yearsChild 7-11 yearsA child of 10 years or more


2-4 years

3-5 years

4-6 years

5-8 years

7-11 years

10 or more

Wheel size








82-100 cm

98-106 cm

104-122 cm

120-130 cm

127-142 cm

140-158 cm

Leg length

30-40 cm

36-44 cm

40-54 cm

52-59 cm

57-66 cm

64-70 cm

*The chart is only for the general reference, as the construction may vary depending on the brand.

Dětské kolo správná velikost

Things to watch out for

  • If your child is not a good rider, make sure to choose a bike that would allow them to reach the ground with their legs.
  • It is not advisable to simply skip a bike size or two, even if the child is relatively tall for their age.
  • The ideal handlebar height is at waist level.

Careless bike selection may cause the child to develop bad riding habits. Don’t forget the protective elements, either! Make sure to give the child the right protective equipment, such as a helmet, pads, gloveslights and reflective elements.

Adult bike sizes

When buying an adult bike, the key factors are the size and the rider’s preferences. Choose the wheel and frame size to match the terrain you generally ride on. A properly sized frame can protect you from neck pain and head, back, and limb aches.

Velikost kola pro dospělé výška rámu průměr ráfku

Choosing the right size in combination with correct settings allows you to use your physical attributes more efficiently and ride better. The bike height can be fine-tuned by adjusting the seat position and handlebars.

Wheel diameters

  • 26" wheels are the smallest size available on normal adult bikes. The lower height gives you a sense of safety and control and makes the bike easier to handle. Suitable for difficult, uneven terrain full of sharp turns.
  • 27.5" is the universal medium size, which offers a combination of decent speed and good handling.
  • 29" wheels are the fastest, but handling a bike this large requires quite a lot of physical strength. The ideal stature for 29" bikes is 175-180 cm and more. Large wheels cope better with bumps on the road and have better traction, so they are used by most athletes.

Velikosti kol 26" 27,5" 29"

Frame height

Frame height is usually measured in inches or sizes S, M, L, XL and is determined by the distance from your foot to crotch or by your total height. Generally, the frame size should be selected so that if the you stand just in front of the saddle, there should be a 5 cm clearance between the top tube of the bike and your crotch. The frame height means the distance between the top of the seat tube and the centre of the bottom bracket.

General bike size chart

HeightFrame height according to size
less than 165 cm15", 16", S, up to 44 cm
160-170 cm17", 18", M, up to 48 cm
170-185 cm19", 20", L, up to 52 cm
185-200 cm21", 22", L, up to 55 cm
over 195 cm23", 24" L, 58 to 60 cm
*The chart is only for the general reference, as in rare cases, the details may vary.
To learn more about how to choose a bicycle, see our article How to choose a bicycle.
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