What size bike for 5-6 year old boy

For most 5–6-year-old boys, start by comparing 14-, 16- and 18-inch bikes. Height and actual fit—not age alone—should decide the size.

Which wheel size should you check first?

A 16-inch bike is the central starting point for this age: the XBikes guide places it at ages 4–7 and rider heights of 40–48 inches (102–122 cm). A smaller 5-year-old may overlap with a 14-inch bike, while a taller 5- or 6-year-old may already fall into the 18-inch range.

These ranges overlap deliberately. If his measured height falls in two rows, compare both sizes in person rather than choosing from the age column. Do not move up merely to leave growing room; an oversized bicycle can make starting, stopping and steering harder.

Measure height and inseam before shopping

Measure the child in the shoes he normally wears for riding. For height, have him stand straight against a wall and measure from the floor to the top of his head. For inseam, place a firm, thin book between his legs with gentle upward pressure, then measure from the floor to the top edge of the book.

Use height to identify the likely wheel sizes in the table. Keep the inseam measurement for the physical fit check: wheel size alone does not reveal frame shape, stand-over clearance or saddle adjustment.

Check the bike with the child on it

Have him try the exact bicycle whenever possible. A suitable candidate should let him stand over the frame without being forced onto his toes or against the bicycle. Seated, he should reach the handlebar naturally rather than stretching, locking his elbows or leaning far forward.

Then check control, not just posture:

• He can mount and get off without an adult lifting or catching him.
• He can hold the handlebar and turn it smoothly while remaining balanced.
• His hands can reach and operate the fitted brake controls confidently.
• He can start, stop and place a foot down without panic or loss of control.

If the height chart suggests a size but he cannot perform these checks, that bike is not a good current fit. Consider the adjacent size and repeat the test. Current confidence matters alongside body measurements, especially for a new rider.

How the supplied XBikes options compare

The XJD Boys & Girls BMX Bike with Training Wheels, 12/14/16" – Blue and the Black XJD Kids Bike for Boys – 12, 14 & 16 Inch Sizes each offer catalog choices labeled 12 Inch, 14 Inch and 16 Inch. That makes their 14- and 16-inch versions useful comparison points for many children in the 5–6 age band, provided the individual fit checks succeed.

These particular catalog options help answer the sizing question because both let you compare the two smaller overlapping sizes identified in the XBikes chart. Neither supplied listing includes an 18-inch option, so a child whose measurements and trial indicate 18 inches should not treat either product as an equivalent substitute.

• XJD Boys & Girls BMX Bike with Training Wheels, 12/14/16" – Blue

  Offers 12 Inch, 14 Inch and 16 Inch catalog options. Its 14- and 16-inch versions are relevant comparison points for a 5–6-year-old whose measured height and individual fit support those sizes.

• Black XJD Kids Bike for Boys – 12, 14 & 16 Inch Sizes

  Available in catalog labels 12 Inch, 14 Inch and 16 Inch. Compare its 14- or 16-inch option only after checking the child's height, inseam, stand-over clearance, reach, brake control and confidence.

Choose between these two products only after selecting the appropriate labeled size. Their supplied catalog categories differ: the blue XJD model is listed under Kids' BMX Bikes, while the black XJD model is listed under Training Wheel Bikes. No further construction, brake, load, assembly or compatibility details are supplied here; consult the exact product manual or a qualified bicycle mechanic for those questions.

Do the final riding and helmet check

Once a candidate passes the stationary checks, let the child demonstrate a controlled start, turn and stop in a traffic-free area with close adult supervision. Recheck reach and control if the saddle or handlebar is adjusted. Follow the exact manual for permitted adjustments, assembly and maintenance rather than guessing at procedures or torque.

A bicycle helmet must fit properly, sit level and have its straps secured according to the helmet manufacturer's instructions. A helmet does not correct a poor bicycle fit, so confirm both independently.

The practical decision for a 5–6-year-old boy

Measure him first. Compare 14 inches at 37–45 inches tall, 16 inches at 40–48 inches, and 18 inches at 43–52 inches; where ranges overlap, trial both candidates. Select the bike on which he has appropriate stand-over clearance, comfortable reach, reliable brake control and confident starts and stops. If those checks point to 18 inches, skip the supplied 12/14/16-inch products rather than sizing down or pretending the sizes are interchangeable.