Enter the axle ratio, transmission gear ratio, and transfer case ratio into the calculator to determine the final drive ratio.

Final Drive Ratio Formula

The following formula is used to calculate the final drive ratio of a car.

DR = AR * TR * TCR
• Where DR is the drive ratio (ratio :1)
• AR is the axle ratio : 1
• TR is the transmission gear ratio : 1
• TCR is the transfer case ratio : 1

To calculate a final drive ratio, multiply the axle ratio by the transmission gear ratio, then multiply this result by the transfer case ratio.

Final Drive Ratio Definition

A final drive ratio is defined as the final ratio between the engine rpm to the wheel rpm of a car or vehicle.

Final Drive Ratio Example

How to calculate the final drive ratio?

1. First, determine the axel ratio.

For this example we will say the axel ratio is 5:1.

2. Next, determine the transmission ratio.

For this example the transmission ratio is 2:1.

3. Next, determine the transfer case ratio.

For this example and most cases this is 1:1 on the high end.

4. Finally, calculate the final drive ratio.

Using the equation above we find the drive ratio to be 10:1

FAQ

What is a final drive ratio?

A final drive ratio is the ratio of the RPM of an engine to the RPM delivered to the wheels of a vehicle.