Calculate engine RPM/vehicle speed and speedometer gear Calculate tire dimensions

Tire revolutions per mile:
If needed, use the tire dimensions calculator on the right to calculate this value

Final drive gear ratio:

Transmission drive gear ratio*:

Output shaft teeth count1:

RPM:

MPH:

MPH:

RPM:

Speedometer gear teeth:

*Click to display a table of transmission gear ratios
194-97 MN12 and 93-98 FN10: 7; all others: 8

Enter tire diameter (inches) or fill out the fields below:
If a tire diameter is entered above, the tire dimensions fields
below will be ignored during calculation.

Treadwidth (mm):

Sidewall:

Rim diameter (inches):

Diameter:

Circumference:

Revolutions per mile:

Compare tire dimensions

Stock Size

Diameter:
If a tire diameter is entered above, the tire dimensions fields
below will be ignored during calculation.

Treadwidth (mm):

Sidewall:

Rim diameter:

Size 2

Diameter:
If a tire diameter is entered above, the tire dimensions fields
below will be ignored during calculation.

Treadwidth (mm):

Sidewall:

Rim diameter:

Diameter:

Tire revolutions per mile:

If your speedometer says 60 MPH,
you are traveling 60 MPH
.

Diameter:

Tire revolutions per mile:

If your speedometer says 60 MPH,
you are traveling MPH.