Enter the number of teeth on the ring gear and the number of teeth on the pinion into the Axle Ratio Calculator. The calculator will evaluate and display the Axle Ratio. 

Axle Ratio Formula

The following formula is used to calculate the Axle Ratio. 

AXR = TRG / TP

  • Where AXR is the Axle Ratio ( )
  • TRG is the number of teeth on the ring gear 
  • TP is the number of teeth on the pinion 

How to Calculate Axle Ratio?

The following example problems outline how to calculate Axle Ratio.

Example Problem #1:

  1. First, determine the number of teeth on the ring gear. 
    • The number of teeth on the ring gear is given as: 25.
  2. Next, determine the number of teeth on the pinion. 
    • The number of teeth on the pinion is provided as: 30.
  3. Finally, calculate the Axle Ratio using the equation above: 

AXR = TRG / TP

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

AXR = 25 / 30 = .833 ( )

Example Problem #2: 

For this problem, the variables required are provided below:

number of teeth on the ring gear = 60

number of teeth on the pinion = 80

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

AXR = TRG / TP = ?