Enter the rear-end ratio and the transmission first gear ratio into the Starting-Line Ratio Calculator. The calculator will evaluate and display the Starting-Line Ratio. 

Starting-Line Ratio Formula

The following formula is used to calculate the Starting-Line Ratio. 

  • Where STLR is the Starting-Line Ratio
  • RER is the rear-end ratio 
  • TFG is the transmission first gear ratio 

To calculate a starting-line ratio, multiply the rear-end ratio by the transmission first gear ratio.

How to Calculate Starting-Line Ratio?

The following example problems outline how to calculate Starting-Line Ratio.

Example Problem #1:

  1. First, determine the rear-end ratio.
    • The rear-end ratio is given as: 2.5.
  2. Next, determine the transmission first gear ratio.
    • The transmission first gear ratio is provided as: 5.3.
  3. Finally, calculate the Starting-Line Ratio using the equation above: 


The values given above are inserted into the equation below and the solution is calculated:

STLR = 2.5 *5.3 = 13.25

Example Problem #2: 

For this problem, the variables required are provided below:

rear-end ratio = 1.5

transmission first gear ratio = 6

Test your knowledge using the equation and check your answer with the calculator above.