Kids Bike Sizes: Four Steps To Finding The Right Size
Using your childs inseam in relation to the bikes seat height is the best and most accurate way to ensure a perfect bike fit. The frame and the wheel size work together to determine the seat height of a bike.
So by selecting a bike based on seat height, versus age, wheel, or frame size, you can ensure a great bike fit for your child even if theyve never had a chance to try out the bike before you buy it! This not only makes riding much easier, but all the experts agree a good bike fit is necessary for safety too!
Here are the four simple steps youll need to follow to finding a kids bike thats the perfect size.
How To Measure Inseam For Bike Size
Bike size can be confusing, especially when it comes to inseam. The inseam is the distance from the crotch to the floor. The different sizes of bikes have different inseams, so it is important to measure your inseam before purchasing a bike. Here are some tips on how to measure your inseam:
Are You Between Two Bike Sizes
If you are exactly between two sizes, no worries! Bikes vary in frame geometry – it depends on the type of bike and/or manufacturer. This allows you to find a bike with the best fitting frame size for you. Also, saddles and handlebars are also height adjustable for adult bikes, so you can customize your bike. Many bikes have an adjustable stem, so you can change the angle of the handlebars until the bike fits comfortably. Lastly, the frame size can influence the driving characteristics, so you can choose the smaller or larger frame depending on the driving style. A smaller frame is generally more maneuverable and agile. A larger frame distinguishes the bike through a quiet and stable road handling, perfect for long journeys. General rule of thumb: the more time you want to spend on your bike, the more accurate you’ll want the fit. In addition, you have to pay attention to the fit. If you’ll be riding off-road, a wrong bike could be a real health risk!
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Debunking Age As A Criterion
Finally, the time has come to debunk one attribute all-too-often named as a determinant for sizing bikes for children: age. As long as the childs physical measurements falling within the parameters outlined on the charts well-matched to the dimensions of the bicycle, age in itself is no objective criterion for determining how well a child will ride. At this point, whether the child is physically coordinated and mature enough in judgment for the bike at hand is perhaps best left up to the childs parents or guardian. Age alone is not a reliable criterion.
How To Measure For A Bike

Properly measuring for a bike is incredibly important and being comfortably matters to both professional and casual cyclists alike.
The key elements to be aware of are:
- Your height
- The lenght of your inside leg
- The frame size of your chosen bike
Knowing these three measurements will enable you to choose a bike thats roughly the right fit for you. The frame of your bike is one of the only elements that cant be changed after all you can raise or lower handlebars and seats, so getting this right really matters.
Similarly to how shoe sizes arent always universal, different frame sizes listed by different manufacturers may not be completely accurate so be sure to check your manufacturers own size guide before making an online purchase.
To help, weve created a bike size chart which should make finding your ideal frame size a little bit easier.
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Getting Your Saddle In The Right Position
An adult cyclist should be able to touch the floor with their tip-toes while sat in the saddle. If you cant reach the floor, your saddle is too high if you can put the entire base of your foot on the ground, youre too low.Here are a few tips to help you get your saddle in the perfect position:
- Sit in the saddle and put the ball of your foot on the pedal with a slight bend in your leg: your leg should not be perfectly straight. Place your other foot on the floor.
- You should find that there are a few inches difference between the saddle height and the size of your frame. Some of the seat post should be showing. Compact frames are smaller so more seat post will be showing and vice versa with traditional horizontal geometry frames.
- Make sure the saddle is level and not sloping forwards or backwards. This can be extremely uncomfortable .
- Tweak the position of the saddle in the rails, moving it until youve got it exactly how you want it. Imagine a plumb line running straight down from the centre of the kneecap through the ball of the foot in the 3 oclock position. This is shown in the image below.
If youre too far forward or back, it will not only be uncomfortable but youll also impact on your pedalling efficiency.
Narrow Down Wheel Size Based On Inseam
Using your childs inseam, find the one or two bike wheel size categories they fall into. In general, as long as your childs inseam is appropriate for the bike, its better to buy a larger wheel size. Larger wheels have more stability and allow more room for growth.
For example, our 5-year-old shown above has an inseam 19.5 inches. Based on the bike size chart below, she could fit on THREE different size bikes! The larger wheels of the 16 and 20 however, will be much better for her as she grows. The next step will help determine which of these two sizes is best.
How To Measure Bike Frame Size
Measuring a classic road bike frame size is a relatively simple task. To measure:
1) Find the top of the seat tube
2) Find the center of the bottom bracket
3) Measure the distance between these 2 points
4) Record this in both cm and inch to find the right frame for you
As you can see on our bike geometry, the ST is the frame size.
Bike Wheel Sizes Explained
If youre looking for a new bike but youre not sure which size wheels you need, youve come to the right place.
In this short guide, I cover everything there is to know about different bike wheel sizes. If you want to learn how to measure a bike wheel size, you can read my short guide here.
Ill explain the benefits different bike wheel sizes offer and any setbacks they have, alongside providing several bike wheel size charts, ISO wheel charts, and much more!
Bikes are an expensive investment, so its crucial you choose a wheel size that fits right, providing you with a smooth, comfortable ride. Ill help you do just that.
At the top of the wheel size guide, I start by explaining kids bike wheel sizes and later in the article, Ill talk you through Adult/standard bike wheel sizes.
You can use the table of contents below to jump to a section you want to learn more about. Otherwise, lets get straight into it!
Measure Your Childs Height And Inseam
The next thing to do is to measure your child. Dont skip this step or guess!
If youre buying the bike as a gift, you should still be able to ask the childs parents to measure them for you. Lie and say youre sewing clothes or something if it must be a secret!
Measure your childs inseam AND their height. Youll want to take the measurements in inches . Make sure to write down those measurements and save them for our next step.
Men Can Also Ride Women
Also, bear in mind that if you are a man and you choose a woman-specific bike, that is just fine and no one needs to know! The reality is that the average male height in some countries is shorter than the average female height in others. For example, average male height in Indonesia is 5 ft 2 in, while average female height in The Netherlands is 5 ft 7 in !
So obviously, we cannot really generalize too much about this matter. Everyone is unique.
Bike Size Chart For Kids
Kids simply cherish riding bikes. Do you remember the sheer excitement of riding your first bike back then? Almost certainly, it is one of the moments you will always remember. It gets kids outside, gets them fit, makes them independent, and most all of riding is enjoyable. These are the bonuses that come along with a present like this. The sweet news is that children can begin riding bikes appropriately from around 3 years old.
Kids Bike
Nevertheless, kids size increases rapidly. Everybody knows this. That is the reason picking the correct bike for your child, can at first appear to be very confusing, but at the same time is important to their having the capacity to ride their bikes securely and with confidence. While choosing a bicycle for a more youthful individual, the most critical thing to ensure is that the kid feels and looks great on the bike and that they think the bike is cool. Do not get your child a bike that they will obviously not like, and expect theyll change their opinions once you get home.
They may, and they may not. It is possible for you to harm your kid emotionally forever by getting them a Destructor 4000 Extreme when the exact bike they wanted to be the Princess bicycle with sparkles and a basket. I have been there, even did it. Kids have never had such a great amount of choice of quality when it comes to bikes. From teenagers to babies, there is a bike for your kid.
Chart source |
Bike Size Based On Your Inseam Length And Bike Size Chart

This is probably the best bike sizing method for most people. It is based on the inseam length that you can measure at home.
IMPORTANT NOTE: The inseam length for choosing a bike size is measured differently from an inseam length for buying pants. Learn more on how to measure it correctly.
Once you measure the inseam length, use it to select the bike size. Most bicycle manufacturers use the seat tube length in their bike size charts alongside many other details, including the standover height.
The standover height is the distance from the ground to the top of the top tube.
If your inseam length is shorter than the standover height, the bike is too large for you.
The clearance, which is the difference between your inseam length and the standover height, should be roughly 1 to 2 inches.
You should have some clearance to prevent injuries caused by accidental stopping on your bike.
So Where Do I Find The Best Bikes And Their Seat Heights
Part of the reason that kids bike sizes are confusing is that there are no bike sizing standards. While the CPSC has rules regarding almost everything else about a bicycle, there are no rules about kids bikes sizes.
To make matters more confusing, most bike companies dont publish the seat heights of their bikes! Not to worry, weve got you covered! Weve measured the seat heights of over 50 different bikes for you!
You can find seat heights on our comparison charts for each size bikes:
Kids Bike Wheels Folding Bike Wheels & Other Small Bike Wheels
Essential Information – Kids Bike Wheel Sizes
Unlike adults bikes, kids bikes are measured by the size of their wheels. Below I explain some of the most common wheel sizes for kids bikes.
If you want to find out about the different kids bike wheel sizes and how to accurately measure and size a bike for a child, youll want to read my Kids Bike Size Guide.
29″ / 700c Bike Wheels
Believe it or not, 29-inch and 700c wheels are the same size and are becoming more popular.
Cyclocross, gravel, hybrid and many mountain bikes are now equipped with 700c wheels for their high top-speed and larger surface contact area .
As youll probably know, virtually all road bikes also use 700c wheels nowadays as they provide an increased top rolling speed compared to smaller wheels and a smoother ride thanks to their decreased attack angle.
Some riders dont enjoy that 29-inch wheels are less manoeuvrable than 26 or 27.5-inch wheels, which is why until recently, they were only really found on road-inclined bicycles.
Whilst both road and mountain bikes utilise 700c wheels, 29 mountain bike rims are understandably wider, providing increased surface contact for more intense off-road sessions.
Just like 28 wheels, 700C wheels have a BSD of 622 mm. 29, 29er, and 700C measurements are marketing terms used to describe the wheels of different bike types.
to learn the most accurate ways to measure your inseam and height. Poorly taken measurements can lead to an inaccurate bike fit.
Look Up The Specs For The Bike You Are Interested In
Just because you think your child probably needs a 14 bike doesnt mean that ANY 14 bike will fit them. Different bikes have different stand-over heights and min/max seatpost heights. Its best to look for a bike that will provide the BEST FIT for your kiddo.
Not all bike manufacturers list the standover height for their bikes. If they do, however, you should compare it to your childs inseam.
The standover height is the height of the top tube of the bike frame where your child will be positioned when standing with one leg over each side of the bike. This means that your childs inseam needs to be AT LEAST as tall as the standover height. Ideally, there will be a little more space than that for your child to maneuver the bike comfortably.
Your child needs to be able to comfortably stand over the top tube of the bike
The other stat that you should absolutely look up is the minimum seatpost height for any bike you are considering. How the minimum seatpost height compares to your childs inseam is dependent on whether you are buying a balance bike, first pedal bike, or a pedal bike for a confident pedaler.
For a balance bike, you want to make sure that the minimum seatpost height is no higher than your childs inseam length. This allows your child to put their feet flat on the ground, to learn to balance and to scoot.
For a balance bike, you want your child to be able to place their feet flat on the ground while sitting on the seat
Balance Bike Guides & Comparison Charts:
Unisex Bikes And Women
On average, females have shorter torsos and longer legs as compared to men of similar height, hence women-specific bikes always have a short top tube along with narrow handlebars & women-specific saddles.
But, people arent average thus a bike must be an ideal fit for you, whether its the female-specific fit or the unisex bike.
Generally, in case you are a bit shorter than almost 5ft 5 or you are feeling too much stretched on the unisex or mens bike before, you might be a bit more suited to the women-specific bike which does offer smaller frame size.
When you are in doubt, then you feel free to have an appointment along with a professional expert who might call you back in order to assist you in finding the proper bike size for you.
What Is Inseam Size
Inseam size is often regarded as one of the most important factors when choosing a frame size. Inseam is simply the measurement from the floor to the highest possible crotch position measured in cm.
Measuring the inseam can be done relatively easily, requiring only 2 people and a book only taking a fraction of time. To begin:
Alternatively, if visiting a store and receiving a professional bike-fit this will be done for you. This is recommended if you do not feel comfortable measuring the inseam or your bike fit size yourself.
Q: Do Bike Sizes Correlate To Kids Ages
A: Yes and no. You can often estimate what size bike your child will need based on their age, but the best way is going by their height. Kids heights can vary quite a bit, what with the growth spurts and all, so using their height instead of age will provide a much more accurate way to determine the appropriate bike size. And of course, you should have your child test ride the bike before purchase when possible.
Cruiser Bike Size Chart
A beach cruiser bike is a type of bicycle that was designed to be ridden on beaches and other coastal communities. They typically have large tires, low seat heights, and comfortable seats. Beach cruiser bikes are usually equipped with coaster brakes, which allow them to be stopped quickly without having to use their hands. They are also made from sturdy materials so they can handle heavy loads while riding on sandy paths or roads. Here is the cruiser bike size chart:
Rider Age |
Tips For Buying A Bike

Before buying a bike, remember to research, think for a while, and answer these three crucial questions:
What do I need a bike for? Ask yourself what you are going to use your new bike for, and over which terrain that will take you – paved roads, gravel, or off-road? City or nature trails? You can find some hints in the Type of a bike paragraph above.
How much do I want to spend? You can not only buy a bike for $300, but also for $3000, so decide on your budget first. That leads us to the next tip…
Do I want a used or a new bike? If you’d like to buy a better quality bike that is unfortunately too expensive, you can always search for used bikes. Just be careful you are not scammed – maybe your friend wants to sell one, or a local shop has some ex-display models?
After finding the type of bike you’d like to buy :
And, if it’s possible:
- Test-ride a few different bikes. Purchasing a bike from a stationary shop has many advantages – apart from testing the bikes, you can ask for advice and recommendations. Don’t hesitate to ask questions that will clear any doubts. Some shops even offer a bike-fitting service that can help you to adjust your new purchase perfectly to your body.