Welcome To ACCU Autoparts Gear Calculators  These calculators are intended to help make the proper gear ratio choice based on  numbers. Novices - put as accurate information as possible in at least the first 4  sections. Advanced - tweak the numbers as required to evaluate. www.accuautoparts.com/calculator.jsp www.accuautoparts.com Factory Original Tire Diameter : Tire Diameter - Use Calculator Below If Needed Factory Original Gear Ratio: RPM @ : Gear Ratio - Use Calculator Below If Needed New Tire Size : Tire Diameter - Use Calculator Below If Needed New Gear Ratio : << Recommeded Ratio to Match Original Gear        Ratio/Tire size With New Tire Size Target Speed MPH : Advanced - Target Ratio for Cruising RPM Redline : Advanced - Target Shiftpoints and Topspeed Ft/Lb Torque In to Pinion Yoke : Advanced - Target Torque Change for Towing Old vs. New Rearend Gear Ratio Comparison   ORIG Ratio OLD Ratio NEW Ratio ORIG Tire NEW Tire NEW Tire Axleshaft Torque Output : Metric Tire Size Conversion WIDTH ASPECT RATIO WHEEL SIZE Height inches Width inches GEAR RATIO CALCULATOR RING GEAR TEETH PINION GEAR Final Ratio Transmission Shiftpoints / Max MPH * Trans Gear Trans Ratio MPH Max @ Redline 3 Speed 1st 2nd 3rd Trans Gear Trans Ratio MPH Max @ Redline 4 Speed 1st NoOverdrive 2nd 3rd 4th Trans Gear Trans Ratio MPH Max @ Redline 4 Speed 1st Overdrive 2nd 3rd 4th Trans Gear Trans Ratio MPH Max @ Redline 5 Speed 1st 2nd 3rd 4th 5th Trans Gear Trans Ratio MPH Max @ Redline 6 Speed 1st 2nd 3rd 4th 5th 6th