How To Measure Road Bike Frame Size

Bicycles are measured using the size of the frame. The size of the bike frame is defined with how long the tube is and the vertical parts that support seat post assembly and the seat. What makes a bike more comfortable is choosing the bike that fits you properly. This will give you good control when you are riding.

If your height is between five feet and eight inches and six feet tall, you are likely to fit properly on an eighteen-inch bike. However, if you are shorter than this then you need to try a bike that is sixteen inches. Otherwise, for those taller people, they need to use a bike that is twenty inches.

How To Measure Road Bike Frame Size

Steps On Measuring The Frame Of A Road Bike

  • Step one: Locate the top of the seat from the frame tube. This is the part that joins the seat and enters on the bike frame. The seat is the position in the bike where the topmost part connects with the frame tube.
  • Step two: You need to find the bottom bracket of the bike. The bottom bracket is the bottom part of the frame tube which is cylindrical and is connected to the tube frame.
  • Step three: Measure from the point where the seat connects with the tube to the center of the cylindrical bracket at the bottom where it connects the frame tube. That is the measurement that determines the size of the bike frame.
  • Step four: Convert your measurement if need be. The measurement can be in inches or millimeters. This can be done mathematically and you can be able to obtain the actual measurements of the bike. This can look like a tedious exercise but is one of the best ways to measure the bike frame size.

Measurement By Your Body Height

Another method that you can use to measure the frame size of your bike is by taking your shoes off and stand next to the bike at about 15 centimeters apart. You can then measure the distance from the bottom to your crotch. Then you can take measurement equipment like a tape measure and calculate the size of your bike's frame.

For example, if the length measured from the bottom to the crotch is seventy-six centimeters, then your bike is a twenty-inch bike. This is achieved by converting these measurements against the right measurement that bike is sized with.

Measuring the head tube length of the bike can determine the size of the frame of the bike. The head tube of a bike is the front point of a bike. This is the part which the fork is inserted to the bike through. However, this is the less measurement that can be used to measure the frame size of a bike, it is also considered too.

The head of the bike is what is considered when choosing what kind of a bike you want to ride. Additionally, this is the easiest kind of bike measurement as you do measure from the top to the bottom or bottom to top, whichever way you feel it’s easiest for you.

Knowing how to measure the size of the frame of a bike and the significance of the measurement helps you when finding the right kind of road bike you want. There is no monetary value that can be put on the comfort you get when on a bike.

However, when riding a bike and having no comfort on it will lead to less riding of the bike and lose interest in riding a bike. All this is contributed by knowing how to measure the size of the frame of a road bike.

Measuring The Bike Frame By Lying Down The Bike Against The Tape

Another way of measuring a bike is lying down the bike against the measurement tape. Although this, the method does sound silly and stupid, it’s one of the easiest ways to measure a bike. The tape is placed from the point where the seat tube connects to the frame tube to the center of the pedal of the bike. This method may be a bit easy as you just record the readings then convert them into inches as required by the measurement of bike frame size.

Measuring Bike Frame By Use Of Suspensions

You can also measure the size of a bike frame by the use of suspensions. Suspensions are the newest class of the mountain bike which are equipped at rear and front of the bike. These suspensions are only fit for a certain kind of a bike according to the bike frame sizes. Identifying or measuring the suspension size of the bike then you can easily identify the size of the frame of your bike.

This is measured from where the seat tube connects to the frame tube to the point where the chain tube connects with the center of rear tears. After measuring and recording that distance, then you can convert it to inches as it is the measurement that is associated with frames of the bike. When riding a bike is very hard to tell the inseam of that bike as it can be big or small and can cause so much damage to you.


The size of a particular road bike is measured according to the size of the frame. A bike frame that fits you well will provide you with comfortable rides. On the other hand, a bit that doesn’t fit you can lead to uncomfortable rides. So, before you consider buying a road bike, it is essential to check the bike sizing and fitting. After all, you don’t want to end up with a bike that doesn’t meet your riding needs.

If you were wondering how you can determine the frame size of a road bike, I have provided you with different methods to help you get accurate frame measurement. You can use any of these methods to find out the size of the road bike. You should also know that the size of bikes differ based on the brand. Basically, if you are between 5ft 8 inches-6 feet tall, a road bike measuring 18 inches will fit you well. For shorter people, you can try 16 inches bikes. Additionally, for taller people, you can get a bike measuring 20 inches or larger.

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