Diff Ratio Calculator. Use this calculator to determine your gear ratio and vehicle s speed in any gear and any engine rpm for best performance. Also calculated is the new gearing you would need in order to return back to your original gear ratio when going to a bigger or smaller tire.
Scroll through the list of popular transmissions to find yours. Drag max rpm slider to adjust the range of the rpm and km h gauges. Use our gear ratio calculator to find the effective gear ratio your vehicle will have with a new tire size.
Choosing the right differential gear ratio will help regain lost power and torque.
Please refer to the tire height calculator to determine your tire height. Choosing the right differential gear ratio will help regain lost power and torque. Tire diameter in inches radius x 2 mph calculate. Enter shift at rpm select gear to shift to and hit shift and trace to run up through the gears recording shift point rpm and km h.
