Enter the input gear teeth and the output gear teeth into the Calculator. The calculator will evaluate the Speed Increase Ratio. 

Speed Increase Ratio Formula



  • SIR is the Speed Increase Ratio ()
  • IGT is the input gear teeth
  • OGT is the output gear teeth

To calculate Speed Increase Ratio,

How to Calculate Speed Increase Ratio?

The following steps outline how to calculate the Speed Increase Ratio.

  1. First, determine the input gear teeth. 
  2. Next, determine the output gear teeth. 
  3. Next, gather the formula from above = SIR = IGT / OGT.
  4. Finally, calculate the Speed Increase Ratio.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

input gear teeth = 20

output gear teeth = 10