How to Choose the Right Bike Size? (3 Methods + Calculator)

Bike Size Chart - How to Choose Bike Size? A row of different bike sizes in front of a wall

In this guide, you will find out how to choose the right bike size. It covers hybrid, mountain, and road bikes, so if you plan to buy a bike online, you are in the right place!

You can use an interactive calculator that recommends a bike size based on your inseam length and bike type. Or you can choose the bike size based on one of the 3 methods I explain below.

All these tools will help you choose the correct bike frame size, so you avoid returning your brand new bike ordered online due to it being the wrong size.

Also, make sure you check the FAQ section, where you will find the answer to the most common questions like:

  • What frame size do I need if I’m in-between sizes?
  • Why is the correct bike size important?
  • Does your age influence the bike size you should get?

Let’s dive in!


Bike Size Calculator

Find the right bike frame size using this frame calculator.
Simply choose the bike type, input your inseam length and get the size recommendation. Learn how to correctly measure your inseam for choosing a bike size.

Choose the Bike Type
How to choose a bike?
mountain bike icon 250px newMTB
Cross-Country, Trail,
and Enduro Bikes
hybrid bike icon 250px newHYBRID
Trekking, Commuter,
and City Bikes
road bike icon 250px newROAD
Road, Gravel,
and CX Bikes
Enter Your Inseam Length
How to measure your inseam?

inch cm


Disclaimer: Please remember that the calculator does not consider your height, which may affect your bike size.


What Bike Size Do I Need?

The following methods are sorted from the simplest to the more complex. Remember that less sophisticated methods are less accurate and vice versa.

If you don’t know what type of bike to choose yet, visit my article on How to Choose a Bike. It contains an interactive guide that will help you with your bike selection.


Method #1: Bike Size Based on Your Height (The Easiest Method)

This is the easiest and fastest method by which you can select the bike size. All it takes is to compare your height with the general bike sizing chart below.

Your HeightBike Size
FeetcmInchescm
4’11” –  5’3″125 – 16213 – 1533 – 38
5’3″ –  5’7″162 – 17415 – 1638 – 41
5’7″ –  5’11”174 – 18316 – 1741 – 43
6’0″ –  6’2″183 – 18917 – 1943 – 48
6’2″ –  6’4″189 – 19519 – 2148 – 53
6’4″+195+21+53+
Bike size chart based on your height.

Unfortunately, this method does not take into account the type of bike. This means it is not as accurate as the methods below. So, you risk that the bicycle won’t fit you perfectly.


Method #2: 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 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.

An illustration of a bike size based on the seat tube length and the standover height
Seat tube length and standover height

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 and emergency stops.

Hybrid Bike Size Chart

Depending on the manufacturer, hybrid bikes use all 3 types of size designations – in, cm, and descriptive sizes (S, M, L…).

Hybrid bike size chart: Choose the hybrid bike size based on your inseam length and the seat tube length
Hybrid bike size chart | Data source: bikesizechart.com

Mountain Bike Size Chart

The size of mountain bikes is usually given in inches or descriptive sizes.

Mountain bike size chart: Choose the mountain bike size based on your inseam length and the seat tube length
Mountain bike size chart | Data source: bikesizechart.com

Road Bike Size Chart

The size of road bikes is usually given in centimeters or descriptive sizes. The following road bike size chart also applies to cyclocross and gravel bikes.

Road bike size chart: Choose the road bike size based on your inseam length and the seat tube length
Road bike size chart | Data source: bikesizechart.com

Method #3: Calculating the Bike Size

As we know from Method #2, the bike size is measured based on the seat tube length.

Therefore, to successfully use this method, you will also need to know the length of your inseam (learn how to measure it correctly).

To calculate the size of your next bike, use the following formulas depending on the type of bike you want.

  • Inseam Length (cm) × 0.685 = Hybrid Bike Size (cm)
  • Inseam Length (cm) × 0.225 = MTB Bike Size (inches)
  • Inseam Length (cm) × 0.665 = Road Bike Size (cm)

1 in = 2.54 cm
1 cm = 0.39 in

Once you get the result, round it up to whole numbers. Then, the result will match the bike size charts above with a slight deviation.

Example of Calculating the MTB Bike Size:

Your inseam length is 33 inches, and you want to buy a new mountain bike. Let’s do the math:

Convert cm to inches: 33 inches × 2.54 = 83.8 cm
Calculate the bike size: 83.8 cm × 0.225 = 18.8 ≐ 19 inches

The size of your new mountain bike should be 19 inches.

Example of Calculating the Road Bike Size:

Your inseam length is 70 cm, and you want to buy a new road bike:

70 cm × 0.665 = 46.55 cm ≐ 47 cm

As you can see, the size of your new road bike should be 47 cm.


How to Measure the Inseam Length?

To measure your inseam length, follow these 5 simple steps or watch the video below:

  1. Prepare a 0.75 to 1-inch (1.9-2.5cm) thick book and a tape measure.
  2. Take off your shoes and stand with your back to the wall.
  3. Put the book in your inseam, firmly pull it up and hold it with your tights. Make sure the book is pressed against the wall on one side.
  4. Measure the length from the top of the book to the floor.
  5. Take the measurement.

NOTE: The inseam for choosing the right bike size is different (it is a few inches longer) from the inseam used to choose the pants’ size. So keep that in mind because inaccurate inseam length may affect the recommended bike size.

Before you proceed to the bike size charts, measure your inseam

Once you measure your inseam length (and eventually also your height), you will be able to compare it with the bike size chart of the specific bike type. Based on it, you can choose the correct size.


Bike Size FAQ


Conclusion

Choosing the right bike size is not difficult when you know how to do it. You can take advantage of the bike size calculator that recommends a bike size based on your inseam and bike type.

Or, use one of the 3 methods I explained:

The first method is the simplest and the least accurate. You only need to know your height and compare it with the universal bike size chart.

The second method is the best method to choose your bike size accurately. First, you need to measure your inseam length and decide what type of bike you want to buy. Then, just compare your inseam length with the hybrid, MTB, or road bike size chart, and that’s it. After that, you can buy your new bike.

The third method requires you to do simple math. You also need to know your inseam length. Once you measure it, you can use special formulas to calculate the size of your next hybrid, mountain, or road bike.

If you are still not sure what size of the bike is right for you, feel free to ask in the comment section below or email me.

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