Choosing a BMX for an 8-, 10-, 12- or 14-year-old

Buying your child a BMX? Their age is a useful place to start, but it will not tell you which size to choose. Two children of the same age can be very different heights and may need different bikes.

Measure your child's current height first. Then use the suggestions below to narrow down the wheel size and, on a 20-inch BMX, the frame's top tube length. These are starting points, not fixed limits for every rider or model.

Which BMX for an eight-year-old?

A 16- or 18-inch BMX is a common starting point at this age. Choose by your child's height:

• 120–135 cm: usually a 16-inch BMX.
• 135–150 cm: an 18-inch BMX may be suitable.

For a smaller beginner near the overlap between sizes, a more compact bike may be easier to control. Your child should be able to steer and lift the bike comfortably, rather than struggle with its size.

Browse 16-inch BMX bikes and 18-inch BMX bikes.

Which BMX for a ten-year-old?

The choice is often between 18- and 20-inch wheels. Height and riding experience matter more than age:

• 135–150 cm: an 18-inch BMX is a useful starting point.
• 145–160 cm: consider a 20-inch BMX with a short top tube of around 19.5–20.25 inches.

At roughly 145–150 cm, either wheel size may be an option. A beginner may find an 18-inch BMX easier to handle. An experienced rider closer to 150 cm who already controls their bike confidently may prefer a short 20-inch setup. Compare the particular bikes before deciding.

Read our 18- or 20-inch BMX comparison for more help at this overlap.

Which BMX for a twelve-year-old?

A 20-inch BMX may be an option, but there is no need to move up simply because your child has turned twelve.

At around 145–160 cm, start by comparing 20-inch bikes with a top tube of approximately 19.5–20.25 inches. At around 160–175 cm, a top tube of approximately 20.25–20.75 inches can be a starting point.

If your child is under roughly 145 cm, check smaller options too. An oversized bike can make bunny hops, manuals and everyday skatepark manoeuvres harder.

On a 20-inch BMX, check TT — the top tube length as well as the wheel size. Two bikes with 20-inch wheels can have very different frame lengths.

Browse 20-inch BMX bikes.

Which BMX for a fourteen-year-old?

A 20-inch BMX is a common choice at this age, but not every 20-inch frame will fit.

For a rider around 160–175 cm tall, compare top tube lengths of approximately 20.25–20.75 inches as a starting point. A shorter rider may need a shorter frame, while a very tall rider may need a longer one.

That is why two fourteen-year-olds can ride the same wheel size but need different frame lengths. The words ‘20-inch BMX’ alone do not tell you whether a bike will fit.

Should you choose a BMX by age?

Use age as a guide, then choose primarily by height. Consider your child's experience, body proportions and how the particular bike feels too.

If the BMX is a surprise gift, find out your child's current height before choosing. That is more useful than their date of birth.

Avoid buying a much bigger BMX for your child to grow into. An oversized frame can make learning tricks harder and leave them with less control now.

For the full height ranges, wheel sizes and top tube suggestions, see our BMX size guide.

What should you check before buying?

Have these details ready when comparing bikes or asking us for help:

• Your child's current height.
• Their age.
• Whether this is their first BMX or they already have riding experience.

These details help narrow down the wheel size and frame length. Browse our BMX bikes to compare the available sizes.

Available models to compare by height

These examples were available to order when checked on 10 November 2026. Use the height groups to narrow your search, then check the sizing advice for the specific model. Availability can change.

Around 120–135 cm

Kink Carve 2027 16-inch BMX has a 16.5-inch top tube. There is an important sizing difference here: its product page gives a suggested rider height of around 96–122 cm. Within this article's 120–135 cm group, that only overlaps at roughly 120–122 cm. It is not a recommendation for the whole group. For a taller child in this band, ask us to check a particular bike before choosing.

Around 135–150 cm

• Radio Saiko 18-inch BMX — 18-inch TT, with 152 mm three-piece chromoly cranks. A shorter top tube to compare with the Düvel.
• SIBMX Düvel 18-inch BMX — 18.5-inch TT and an Odyssey G3 gyro, which lets the bars rotate without winding up the rear brake cable.

Both product pages suggest roughly 135–149 cm. Near 150 cm, compare reach and control rather than treating the rounded group boundary as a guarantee of fit.

Around 145–160 cm

• SIBMX Draak 20-inch BMX — 20-inch TT, with a suggested rider height of around 145–160 cm. A beginner option with a fitted gyro.
• FitBikeCo. PRK XS 20-inch BMX — 20-inch TT, 160 mm three-piece chromoly cranks and a U-brake with gyro. Its product page suggests around 145 cm and above and lists it for intermediate riders.

Around 160–175 cm

• Mafiabikes Kush2 20-inch BMX — 20.4-inch TT, listed as a beginner model for riders around 150 cm and taller. Compare the reach for the individual rider.
• Cult Gateway 2026 20-inch BMX — 20.5-inch TT, 170 mm three-piece chromoly cranks and sealed hubs. Its product page suggests riders over approximately 160 cm.

The 20-inch figure is the wheel size. TT describes the frame length; neither measurement alone guarantees that a bike will fit.

Before the first ride

Choose a properly fitted helmet and suitable protective pads. Read our BMX assembly and safety information before your child starts riding.