The first time a child pedals away without training wheels, it’s a serious milestone. On top of indicating that your little one now has more freedom and independence than ever before, it’s also a sure signal that you’ll soon be upgrading their bike as they continue to grow.
But, as you eyeball the rows of colorful two-wheelers decked out in bold colors, you’ll likely ask yourself, “What is the best bike size for a 5-year-old?”
How Kid’s Bikes Are Measured
Unlike adult bikes, kid bike sizing is based on the diameter of the wheel. Starter balance bikes have the smallest wheels available, at 10-inches.
From there, the wheel diameter increases in 2-inch increments up to 24-inches before transitioning to adult sizes.
For the safest and most comfortable ride, you can’t just rely on your child’s age. This is especially true if your child is bigger or smaller than your average kindergartener.
Instead, it would be best to reference several different measurements, including the child’s height, inseam, the bike’s wheel diameter, and seat height.
Choosing the Best Size Bike for 5 Year Old
When choosing the best bike for a 5-year-old, use their age as a general starting point.
Referring to our Kids Bike Size Chart, you can assume that a kindergartner would need a wheel diameter between 12″ -16.” Bikes within that range will also be weighted appropriately for the child to maneuver without being too heavy.
Now that you have a starting point, start measuring!
Measure Their Height
Have your child take off their shoes and stand with their back against the wall. Then, mark the top of their head on the wall with a pencil. Measure from the floor to that mark in inches and write it down for your reference.
The average 5-year old is typically between 3’3″ -4′ tall.
Measure Their Inseam
After getting your child’s height, you’ll likely be able to eliminate one or more of the wheel size “brackets.” To get an even more precise fit for their bike, you’ll also want to measure their inseam or the height from the bottom of their foot to the bottom of their zipper.
This number will help you figure out how tall the bike’s seat post can be while still being safe to ride for beginners.
Jot that number down next to the child’s height, and take it, along with a measuring tape, with you when you’re choosing the bike.
Find a Bike Within the Correct Wheel Range
Once you’re in the bike shop, hunt down a few options within the correct wheel range based on the age/height/wheel diameter chart.
Then, you can further eliminate any options that weigh more than 70% of the child’s weight.
For example, assume your child weighs 45 pounds. Seventy percent of 45 is 31.5 pounds, so you can nix any bikes that weigh more than that from your pool of possible options.
Otherwise, controlling the bike can be unwieldy and potentially dangerous.

Measure the Seat Height
The last step is to check the best fit based on seat height.
If your child is not with you, their inseam height is critical.
The standover height, or how tall the top “tube” of the bike is, should be at least 2″ shorter than your child’s inseam to allow them to maneuver the bike comfortably when they’re not pedaling.
Depending on your little one’s skill level at the time of purchase, seat height priorities change.
If they’re still very new to biking, choose a short enough seat for the child’s feet to stay flat on the ground when they are seated. That way, they can comfortably scoot along while they get used to pedaling.
On the other hand, if your child is more confident in their biking abilities, choose a bike seat that allows their toes to touch the ground or around 2″ -3″ above the inseam height.
Your greatest chance for finding the best size bike for a 5-year-old is to bring the child with you and let them take them for a test ride—but that’s not always possible when you’re shopping for a gift. In that case, adjustable seats are particularly handy.
Most kids’ bikes have adjustable seats and handlebars, so opt for one where your child is comfortable in the lowest setting. As your child continues to grow, you can adjust the bike to keep up with their needs, ensuring years of fun without breaking the bank on new bikes every year.
Related: Best Way to Teach a Kid To Ride a Bike
Final Thoughts
Use a variety of measurements to choose the best size bike for a 5-year-old, including the child’s height and inseam. Narrow down your options by referencing a size chart and eliminating any wheel diameters that fall outside of the age and height range.
Then, focus on a seat that allows your kiddo to sit comfortably – whether that’s flat-footed for beginners or on tiptoes for experienced bikers.