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How to Measure a Bike

Every responsible citizen nowadays is trying to reduce the use of fuel-burning vehicles and increase more and more use of bikes, as it is very good for the human race and Mother Nature together.

As per the recommendations of the specialists, bike riding is very good for health when it is in the perfect measurement. A bike with the right measurement can be very good for joints and bones.

The difficulties are to choose the right bike with the right measurement. Because of many varieties and different measurements available in the market, it is almost like doing scientific research.

But the fact is, it is not as difficult as it shows. Only because of not knowing the right formula of choosing the bike of your measurement, IT SEEMS HARD.

Perfectly measuring the bike is just knowing some tricks and bike size charts. Your body measurement is the main thing to keep in mind when measuring your bike.

Below here, we will help you get the formula to know how to measure a bike along with some very helpful bike size charts and other important charts.

Know What You Want?

It is very important to know about the kinds of bikes before you approach to choose your bike. Measuring bikes differ according to the difference of their kinds. The kids of bikes are:

Mountain Bikes

Those bikes are with the heavy suspension to rule on the rocky mountain trails. The tires of those bikes widen 26 inches to 29 inches and they are knobby in structure, which helps them to be ridden smoothly in loose dirt and high-over obstacles.

Those bikes are recognized as mountain bikes but they can also be ridden on roads, which will feel you like driving SUV on roads.

Road Bikes

Road bikes are the bikes with slim tires and the most popular variety of the world of bikes. They are best known for their speed. Those bikes consist of down-turned handlebars. They can glide on the roads very easily because of their slim tires. They are very much suitable for long rides and those are the bikes used for racing also.

Time-Trial Bikes (Triathlon)

Those bikes are specialized ones designed for triathlon or time trial racing. Their front handlebars are bull-horn shaped and also have aero bars. Those bikes are designed heavily focused on aerodynamics. Their aerodynamic structure helps them to achieve the goal in time-trial racing.

BMX Trick Bikes

These are the bikes having a specialty in their name means BMX stands for Bicycle Motor Cross. BMX bikes are single speed bikes raced through dirt ramps like motorbikes. Those are short bikes having 20 inches of wheelbase. These bikes are best known for their strong built quality. Those bikes are the best choice for who intends to do tricks and jumps with bikes.

Cyclocross Bikes

Cyclocross bikes structure is quite like road bikes and they also have down handlebars. Their only difference with the road bikes is they have wider knobby tires. Those bikes are designed to be raced on dirt trails and roads together. They are in one word do-anything bike. It is a commuter biker bike also to do your daily works.

Know the Bike


Not only choosing but also knowing about the bike structure is very very important for perfect measurement. Means to know about the frame of your bike is important. Three key features are there in the frame to reach the correct measurement. They are:

Head Tube

This is the vertical tube in front of your bike below the handlebar.  The fork which holds the front wheel inserts through the head tube. Taking its measurement is easy from all just from top to bottom. Its positioning affects the handlebar.

Top Tube

The top tube is the bar from between your legs from below the seat post to the head tube. Its measurement is very important because you reach to the handlebars depends on its sizing.

Seat Tube

This is the part starting below the head of the top tube to your pedal section. The importance to measure it because your legs reach to your pedal perfectly depends on it.

Know Yourself

Besides knowing the bike, to know which parts of your body structure should be measured to be contrasted with the bike to get the right measurement is also very important. They are:

Your Height

To know your perfect height is very important for the measurement of your bike. If you know your height already measure it again perfectly and convert it to inches and centimeters. The information’s will be needed for further approach.

Your Inseam

Measuring inseam correctly is a must to measure the bike correctly. Some people use their pant to measure their inseam but the size of the pant differs so it is more relevant to measure it correctly with measuring tape from your body.

Stand spreading your legs 6-8 inches and place a hard substance there. Now with the help of a measuring tape take the measurement from the pubic bone to your foot from inside.

Your Torso

Measuring your torso length is also important when choosing a road bike. To measure your torso, place the tape from your groin to the ‘V’ point of your throat.


Your Arm

Measure your arm from the end of the collar bone to the middle your palm.


The Formulas to Be Used

Formula 1: This formula is applicable for measuring your road bikes.

  • Height of your inseam*0.67= the perfect length of your seat tube

Formula 2: This formula is applicable for mountain bikes.

  • Height if your inseam*0.67= result – 4/5 = perfect length of your top tube
  • If the bike seller is giving you the frame size by seat tube length multiply your inseam size with 0.185.

Note: These formulas will help you find the answer to the question of what size is my bike?

How to Measure Bike Size

Measurement of Different Bikes with Bike Size Chart Inches

Below here you will get almost all measuring information’s about how to measure your bike along with bike height charts.

Mountain Bikes


Mountain bikes are specially designed to survive heavy shocks and give the rider a good comfort. But a right measurement of the frame is very important to get the expected result. The best way to get your goal is to use the formula. For example:

If your inseam is 32 inches :-{( 32inches *0.67= 21.44 – 4inches = 17 inches)}

Then you need a 17 inches top tube in your mountain bike.

If the formulation is bothering you no need to get tensed here is the chart of mountain bike measurement to make it easier:

Your Height

Your Leg Inseam

Suggested Frame Size

4`10”-5`1”148-158 cm24-29”61-73 cm14″XS
5`1″-5`5″158-168 cm25-30”63-76 cm15” / 16″S
5`5″-5`9″168-178 cm26-31”66-78 cm16” / 17″M
5`9″-6`0″178-185 cm27-32”68-81 cm 17″ / 18″L
6`0″-6`3″185-193 cm28-33”71-83 cm 18″ / 19″XL
6`1″+193 cm+29”+73 cm+ 20”+XXL+

Those are just estimated measurements when choosing your bike, give importance to your comfort. Ride it must before you buy it.

Road Bikes


Road bikes are the most famous and speedy bikes with skinny tires.  They are used for racing on the roads mostly and they come with the highest size. Most of the professional racers use this kind of bikes.

To measure the perfect road bike you should use this formula. For example:

If your inseam is 34 inches :-{( 34inches * 0.67 = 23 inches)}

Your road bike seat tube length will be 23 inches.

If math feels hard no tension our chart given below will help you.

Your Height

Your Leg Inseam

Suggested Frame Size

4`10”-5`1”148-152 cm24-29”61-73 cm47-48 cmXXS
5`1″-5`5″152-160 cm25-30”63-76 cm49-50 cmXS
5`5″-5`9″160-168 cm26-31”66-78 cm51-54 cmS
5`9″-6`0″168-175 cm27-32”68-81 cm 54-56 cmM
6`0″-6`3″175-183 cm28-33”71-83 cm 58-60 cmL
6`1″+183-191 cm29”+73 cm+ 62 cm+XL+

All the measurements given here are estimated. Always give comfort precedence over the measurement.

BMX Bikes


BMX bikes are bikes with the strongest built quality. Those bikes have to go through hard situations. Professionals use them to perform rough jumps and tricks.

To get perfection when doing the tricks correct measurement is very much important. Our chart below will help you to get your required bike.

Biker Height

Suggested Race BMX Size

Suggested Park BMX Size

< 4’4”< 132 cm


16” Wheel
4`2” - 4`10”127-148 cm


18″ Wheel
4’6″ - 5’1″137 – 155 cm


20” Wheel 18 - 19.5” top tube
5`0″-5`4″152-168 cm


20” Wheel 19.5 - 20.25” top tube
5`2″-5`6″157 - 168 cm

Expert XL

20” Wheel 20.25 – 20.5” top tube
5`3″-5`8″160-173 cm


20” Wheel 20.5 – 20.75” top tube
5`7″-6`0″170 - 183 cm


20” Wheel 20.75 – 21” top tube
6`+183 cm+


20” Wheel 21”+ top tube

Time-trial Bikes


Time-trial bikes are specially made to achieve the goal within time. They are designed to make you perform your best when in a challenge. They are designed focused on aerodynamics.

They are made to reach the goal, without perfect measurement which is quite impossible. To achieve its goal it must have to synchronize with the rider’s body. Out chart below is for you to find your perfect triathlon bike.

Rider Height

Suggested Triathlon Frame Size

Feet & InchesCentimetersFrame Size (cm)Frame Size
4`10”- 5`0”148 cm - 152 cm47 cm - 48 cmXX-Small
5`0″- 5`3″152 cm - 160 cm49 cm - 50 cmX-Small
5`3″- 5`6″160 cm - 168 cm51 cm - 53 cmSmall
5`6″- 5`9″168 cm - 175 cm54 cm - 55 cmMedium
5`9″- 6`0″175 cm -183 cm56 cm - 58 cmLarge
6`0″- 6`3″183 cm -191 cm58 cm - 60 cmX-Large
6`3″ - 6`6″191 cm - 198 cm61 cm - 63 cmXX-Large

Cyclocross Bikes


They are also known as hybrid bikes. They have the body almost same like road bikes but also have knobby tires. They are versatile bikes to use anywhere. They can be used as commuters also. Those bikes can be your regular partner.

So, it must have to be in the correct measurement must as it is you, regular partner, to keep your joints fit. Below here the chart according to body measurement is given to help you choose your partner.

Your Height

Your Leg Inseam

Suggested Frame Size

4`10”-5`1”147-155 cm24-29”61 - 73 cm14″XS
5`1″-5`5″155-165 cm25-30”63 - 76 cm15”S
5`5″-5`9″165-175 cm26-31”66 - 78 cm16”M
5`9″-6`0″175-183 cm27-32”68 - 81 cm 17″L
6`0″-6`3″183-191 cm28-33”71 - 83 cm 18″XL
6`1″+191 cm+29”+73 cm+ 19”XXL+

All the information’s given is to just help you find your desired bike because we want you to keep you healthy and to save our mother earth. Improper bike fits are also injurious to health.

When global warming is the warmest issue and you care for your mother earth, riding a bike is the best option to be the savior.

Every year only vehicle emitted smokes are responsible for thirty percent of US global warming emissions. There is no other option than using bike more than dangerous smoke emitting vehicles to reduce pollution.

The good news is the number of cyclists increased by 43 million to 47.5 million in the years between 2015 to 2017. The number is positively increasing over the years.

So, why you will not contribute to your earth?

Note: Measuring the bike you need is complete doesn’t mean your task is complete. The wheel is another important issue for biking. So, to get your ultimate choice you must have to know how to measure a bike wheel. All the issues discussed are researched and relevant. The charts of the bike measurement given are all estimated. Sometimes it differs because of the manufacturers.

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