Use our gear ratio calculator to find the changes to gear ratio when going to a different tire size. Both the effective and new gear ratios are calculated.
Use our gear ratio calculator to find the effective gear ratio your vehicle will have with a new tire size. 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.
Input your stock and new tires sizes along with your original gear ratio. Click "Calculate" to find your new effective gear ratio and the gear ratio needed to return your vehicle back to stock gearing.