How to find the perfect bike size? — Bike hacks


Nothing makes for a great cycling experience than finding the right bike. A bike that adapts to your measurements, your goals and your dreams takes your comfort to the next level. But, finding a perfect match is sometimes a nightmare for beginners.

How big should the frame be? What about inseam length? What size bike do I need? What if I am wrong about the size of my bike? If questions like these are on your mind, we have a solution. A good bike size calculator!

bike size calculator

With our bike size calculator you can easily calculate the right bike size in less than 15 minutes. Just choose the type of bike you’re riding, enter your waist and inseam measurements, and let us do the magic.

We’ll recommend a few bike sizes for you to consider. So you can find the perfect fit depending on the frame size of the bike. Also see the bike size chart below for more information.

Here’s what you need to do.

Step 1: Know your bike type

The first step is to choose an appropriate type of bike. To help you make this decision, below is a brief description of four popular types of bikes.

1. Road bikes

Road bikes are designed for smooth surfaces only. These are general city bikes for regular bike paths and cobbled streets. Thanks to their narrow tires, they are much lighter than other types of bikes.

2. Gravel Bikes

Gravel bikes are all the rage these days. These bikes are a type of road bike, but they can also handle varied terrain and tipsy roads. gravel bikes are ideal for touring, running errands and commuting.

3. Mountain bikes

If you are biking through off-road terrain and mountainous region, consider opting for a Mountain bike. These bikes have wide tires, flat handlebars and suspension for better grip.

4. Hybrid bikes

Hybrid bikes are a hybrid of mountain bikes and racing bikes. They are generally low maintenance, and depending on the model, you can use them recreationally, for commuting, or for commuting.

Of course, there are also other types of bikes that we’ve left out – folding, BMX, etc. However, these four types are more than enough for a beginner. Once you have defined the type of bike you want, next comes the measuring part.

Step 2: Take your measurements

Now, to find your perfect match, you need to take three types of measurements. These are:

1. Standing measurements

These measurements include inseam, sternal notch and height. wear your cycling clothes, take off your shoes, stand against a wall and take the following steps:

crotch – Put a ruler or a book between your legs. This is your inseam level. Now measure the distance from the floor to the top of the book (or ruler).

Measure several times to make sure you don’t make a mistake. Do not use your jeans inseam measurement as it is at least 2 inches shorter than your actual inseam.

Sternal notch – The sternal notch is the bony “V” shape at the base of your neck. It is located between your collarbones. Measure the distance between the top of your sternal notch and the floor.

Height – Place a book or ruler on top of your head. Mark the wall where it rests on your head. Measure the distance from this point to the ground. This is your actual size.

2. Measurements of your arms

Next, you need to find the length of your arms. Here’s how you can do it easily:

Hold any cylindrical object like a pencil in your fist. Now extend your arm forward, palm down, so that it is parallel to the ground. Make sure you are not hunching your shoulders.

Now measure the distance between the side of your rib cage and the side of the pencil. Do this process with both your arms, then calculate the average.

3. Seated Measurements

Finally, you need to find your leg and torso measurements. To do this, sit on a chair. Make sure your back is straight and your pelvis touches the back of the chair.

Your femur should be parallel to the ground and your tibia perpendicular. Now take a level for the following measurements.

Legs – To measure the legs, press on the side of your knees. Slowly slide your thumb away from your leg until you catch a bony protrusion.

This will be under the base of your kneecaps (outside the lower legs). Mark this point with the level and measure its distance from the ground.

Torso – Locate your AC joint (aka acromioclavicular joint). It’s kind of a bony bump on top of your shoulders. Place the level on your AC, making sure it stays level.

Now measure the bottom of the level to the top of your chair. Repeat this process for both sides of your body. Average of the two measurements for a more accurate number.

Step 3: Calculate the frame size of the bike

The last step is to calculate the frame size of your bike. This is the measurement from the middle of the bike’s bottom bracket to the junction of the saddle and its top tube.

However, the top tube is not always horizontal, for example if you have a compact frame bike. You must measure from an imaginary horizontal top tube in this scenario. Remember that some bike manufacturers take measurements from the middle of the top tube, not the top.

Additionally, some bikes come with bottom brackets at different height levels. So you can have two bikes with the same frame size, but with different standover heights.

You can also calculate your bike frame size using a simpler method. Simply measure the inseam in centimeters.

Once you have that figure, multiply it by 0.665 for road bikes, 0.575 for mountain bikes, and 0.645 for trekking bikes. Usually mountain bike frames are smaller than road bike frames.

To convert these numbers to inches, simply divide each by 2.54. Very easy! Plus, this bike size calculator is great for both men and women.

wheel size Age Height crotch
12″ 2-3 years 2’10”-3’4″ 14-17″ 35-42cm
14″ 3-4 years old 3’1″-3’7″ 16-20″ 40-50cm
16″ 4-5 years 3’7″-4’0″ 18-22″ 45-55cm
18″ 5-6 years old 3’9″-4’3″ 20-24″ 50-60cm
20″ 5-8 years old 4’0″-4’5″ 22-25″ 55-63cm
24″ 7-11 years old 4’5″-4’9″ 24-28″ 60-72cm

General tips for getting the right size bike

Remember that your bike should suit you, not the other way around. Sometimes a frame is designed to suit different people. Therefore, once you get the right frame, make sure everything else fits your body.

Next, adjust the seatpost height as needed. Your knee should be slightly bent as you pedal. This position ensures optimum power output with minimal effort and avoids long-term knee problems. The only downside is that you can’t reach the ground with your feet.

After that, think about the position, size, cranks, handlebars and saddle position of your stem. Your options are limitless if you can afford to swap out different bike parts. It can truly transform your bike and your cycling experience.

Final Thoughts

With all the measurements in hand, you should have no trouble finding a suitable bike. We always recommend getting a professional fit.

It might be a bit pricey, but if you make it a hobby, the comfort can be worth every penny. Your next option is to go for a ride a few times to master your bike.

You can adjust different parts if you feel any discomfort. This method is generally a more suitable option for recreational cyclists. Good luck and good driving!

Frequently Asked Questions (FAQ)

What if I got the wrong bike size?

In this case, try to send your bike back to the seller. If this is not possible, you can try to compensate by:

  • Move your saddle slightly forward or backward on the bike
  • Change your body position by getting a bit shorter or longer stem
  • Get a longer seatpost

How to size a child’s bike?

People often wonder what size bike my child needs. Well, the fit of the bike differs for kids.

Additionally, bike sizes are also expressed differently for children. It is usually determined by wheel size, not frame size. Below is a general estimate of the size bike that will fit your child.

Note: Inseam and seat post height may vary from manufacturer to manufacturer.

For what height is a 26 inch bike suitable?

It depends on many factors. However, generally speaking, 26-inch bikes are good for kids and adults around 5-6 feet tall.

For what height is a 28 inch bike suitable?

Again, it depends on many factors such as physical attributes, weight, etc. However, 28 inch bikes are suitable for people who are at least 6’0” to 6’3” tall


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