What size is right?

Where to start

If Goldilocks were to try out three bikes instead of three bowls of porridge—there would still be one that’s just right. For every kiddo, there’s a bike designed to be the perfect fit, one that’s not too small or too big. We may be talking small increments here (mere inches), but even an inch or two can be the differentiator between fun and frustration. That’s why it’s so important to buy a bike that fits your child properly. Goldilocks may not have had any guidance on which porridge to try first, but you’re in luck, we have a way to help you find which bike will be the perfect fit!

The woom bike finder allows us to give you our best recommendation by simply inputting your child’s size, age, and skill level.

Tips for using the woom bike finder

The woom bike finder (which can also be found on our homepage!) is more than meets the eye. While it may seem like we’re just using a few simple calculations, we actually have an advanced sizing system derived from data on children’s anatomy. This is the data we use when designing woom bikes, so it makes sense that we use it to help you find the perfect fit! Throughout all the data we could potentially gather, your child’s height and skill level are the most valuable.

After inputting height, there will be three different skill levels. This selection should be based on how your child’s height compares to other kids of the same age.

For reference, here’s a handy breakdown:


Less than 45th percentile


45th-75th percentile


75th percentile

You can also view the woom inseam chart (which we’ll get to soon!) to check the ideal height ranges for each woom bike. The inseam chart is especially helpful if your child’s measurements fall closely between two sizes.

After inputting your child’s age and height, it’s time to input their skill level. There will be a choice: Beginner or Advanced.

These are the general guidelines we use to differentiate a beginner Rider from an advanced Rider:


A beginner has less experience riding and may even be hesitant to hop on the bike. This Rider may be unable to catch their initial balance, start pedaling, or have difficulty turning.


An advanced Rider is already on the get go. They’re very comfortable with mounting and dismounting the bike, pedal like a pro, and know how to take a turn. They’re also comfortable and knowledgeable about braking.

Note: We highly recommend that all Riders on balance bikes, or those transitioning from a balance bike to pedal bike, are to be classified as beginner Riders.

Once you have age, height, and skill level inputted—your Rider is ready to roll—literally. Now it comes to the fun part: Choosing the perfect color!

The woom inseam chart & tips for measuring

After using the woom bike finder, you may want to consult our inseam chart to confirm the recommended size. It never hurts to be too sure! And as we mentioned, this is particularly helpful if your child falls closely between two sizes.

What is inseam length? Well, it’s the distance from the inner thigh to the floor. It's important to know this because these measurements align with how your child’s legs will fit from saddle to ground.

Here's how to measure your child's inseam as accurately as possible:

  • Have your child stand up straight against a wall wearing the shoes and pants likely to be worn while riding a bike
  • Take a hardcover book and place the spine of the book (facing upward) at your child’s crotch using the same slight pressure that would be applied by a bike saddle while riding
  • Mark the edge of the book's spine on the wall in pencil
  • Now, measure the distance from the floor to the marking as vertically as possible with a measuring stick (or tape measure if that’s all you can find!). This is your child’s inseam measurement in inches
  • Compare the measurement with the minimum inseam lengths in the table below


Rider's Inseam Range

Rider's Height Range

woom 110"-14.4"31"-40"
woom 1 PLUS14.8″ - 18.5″37″ - 43″
woom 216″ - 19.1″37″ - 43″
woom 319.1″ - 25.2″41″ - 47″
woom 422.1″ - 27.9″45″ - 51″
woom 526.4″ - 32.3″49″ - 57″
woom 629.5″ - 37.4″55″ - 65″
woom OFF 422.8″ - 28.7″46″ - 51″
woom OFF 527.8″ - 33.7″50″ - 57″
woom OFF 630.3″ - 37.8″55″ - 65″
woom OFF AIR 422.8″ - 28.7″46″ - 51″
woom OFF AIR 528.3″ - 34.3″50″ - 57″
woom OFF AIR 630.7″ - 38.2″55″ - 65″
woom UP 528″ - 33.5″50″ - 57″
woom UP 630.9″ - 37.4″55″ - 65″

Size Overlap

If your child might fit two sizes, do you go bigger or smaller? The most common question our customer experience team receives is about the right size for a child’s first pedal bike: A woom 2 or a woom 3?

The answer? We’ve often found it’s better to shoot for the stars with the smaller bike than to opt for the one that’s just a little too big. Even if a child can confidently whiz around the neighborhood on a balance bike, the transition to pedals involves learning how to pedal while simultaneously applying the skills they already know: Balancing, steering, braking, and making turns. At first, this will be a challenge that your kiddo will need to master in order to gain the ever-important sense of security.

Pro's & Cons

larger bike will be harder to stop and start, and it’ll also often require its Rider to stand on their tiptoes. Children may feel less confident and comfortable if that’s the case. This could discourage kiddos from learning to ride or enjoying the bike. A too-big bike is less ideal for off-road riding as well.

If a Rider is truly on the cusp of needing a larger size, there are a few upsides: The child will have a better position for efficient pedaling and will be able to use the bike longer before moving up to the next size.

smaller bike will be easier to maneuver and less intimidating, especially for beginners. The Rider will learn to pedal not only sooner, but with great confidence. The disadvantage here, once again, is that the child won’t be able to use the smaller bike for as long. But wait—we have some news about moving up a size: upCYCLING! Our upCYCLING Membership allows you to easily and affordably size up when it’s time.

Sizing up

We all know just how fast kids grow. Many members of the woom community wonder how much use their child will get from a woom before it’s time to buy a new bike and size up.

We’ve found that children will fall in between the ideal height range for a bike (see the inseam chart!) for about two years if the bike is purchased when the child is at the lower end of the height range.

While sizing up every two years may seem frequent, a woom bike is truly an investment for the long term, even when purchased for the short term. woom bikes are made to stand the test of time, both design and wear-wise. Not only is it common to see our customers hand down their bikes to the next Rider in the family, we also see woomsters reselling their bikes. A slightly used woom bike can sell for up to 80 percent of its purchase price. And remember, upCYCLING is always an option—one that will provide you with a 40 percent return of your original purchase that’ll be applied to the next model.

Skipping a size

If your child is already confidently riding a woom 2, woom 3, or woom 4, you may be wondering whether you should skip a size when you buy your next bike.

We generally advise against skipping a size. Even if your child’s confidence is sky high, you should keep in mind that skipping a size not only means riding on a bigger frame, but also safely managing more weight. Handling a smaller bike will always be easier for a child.

Our mission

Our mission is to empower kids to love riding a bike. A love for cycling can only be achieved when a child feels safe and secure on a bike.