Crawl Ratio Calculator

Enter the transmission ratio, transfer case ratio, and the axle gear ratio to calculate the crawl ratio.

Crawl Ratio Formula

The following formula is used to calculate a crawl ratio.


  • Where CR is the crawl ratio
  • TR is the transmission ratio
  • TCR is the transfer case ratio
  • AGR is the axle gear ratio.

Crawl Ratio Definition

A crawl ratio is a measure of the number of rotations an engine makes in order to turn a tire one full rotation.

Crawl Ratio Example

How to calculate a crawl ratio?

  1. First, determine the transmission ratio.

    Measure the transmission ratio.

  2. Next, determine the TCR.

    Calculate the transfer case ratio.

  3. Next, determine the AGR.

    Calculate the axle gear ratio.

  4. Finally, calculate the crawl ratio.

    Calculate the crawl ratio using the equation above.


What is a normal crawl ratio?

Normal crawl ratios on cars range from 20:1 to 30:1

crawl ratio calculator
crawl ratio formula