Bike Gear Ratio Calculator

Formula

To calculate the Gear Ratio (GR):

\[ GR = \frac{T_f}{T_r} \]

Where:

\(GR\) is the gear ratio
\(T_f\) is the number of teeth on the front chainring
\(T_r\) is the number of teeth on the rear sprocket

What is Gear Ratio?

The gear ratio of a bike is the ratio between the number of teeth on the front chainring and the number of teeth on the rear sprocket. It determines how many times the rear wheel turns for each turn of the pedals.

Example Calculation 1

Let's assume the following values:

Number of Teeth on Front Chainring = 50
Number of Teeth on Rear Sprocket = 25

Using the formula:

\[ GR = \frac{50}{25} = 2 \]

The gear ratio is 2.

Example Calculation 2

Let's assume the following values:

Number of Teeth on Front Chainring = 42
Number of Teeth on Rear Sprocket = 21

Using the formula:

\[ GR = \frac{42}{21} = 2 \]

The gear ratio is 2.