How To Measure A Bike Frame

There may be times when you need to know how to measure a bike frame. Some colleges require their students to register their bicycles if it is their primary mode of transportation to and from the campus. Many times the registration paperwork will require you to list the size of your bike. You may also wish to purchase a bicycle slightly larger or smaller than your current bike to find one that fits your stature better.

Supplies you will need:

• Tape measure
• Calculator

1. Look for a bike frame sizing label before measuring. While it is not standard on all brands of bicycles, there may be a label that lists the frame size on the bar that connects the seat to the pedal crank system.
2. Locate the center of the crank. The pedal crank system is located at the point where three frame tubes come together. It is also the center of the foot pedal system. 
3. Place the tape measure at the center of the crank. This is the starting point for the bike frame measurement.
4. Pull the tape measure to the top of the seat tube. This is where the three tubes join at the top of the bike. It is located beneath the seat.
5. Determining the bike frame size. The reading between these two points is the bike frame size in inches. Some manufacturers use the metric system when sizing and labeling their bicycles. In this case take the number in inches and multiply it by 2.54. This will give you the frame size in centimeters.