Enter the maximum safe engine RPM. Enter the tire size diameter. Enter the differential gear ratio and the transmission gear ratio. Click on Calculate Potential Speed. The value will be returned in both miles per hour and kilometers per hour.
Multiply the circumference by the object's angular speed, measured in rpm. For example, if it rotates at 400 rpm: 87.98 × 400 = 35,192. This is the object's surface speed, measured in inches per minute.
Engine RPM divided by total gear ratio, multiplied by the tire diameter and converted for units of measurement, gives vehicle's speed of travel.