Gear and Tire Calculator
To use the Tire Calculator, enter the top part of the
data into the form. For Example P255-50R-15
Would Enter 255 for the
Width, 50 for the Aspect
Ratio and 15 is the
Rim Diameter.

This page will allow you to enter some basic
parameters, Gear, Trans Ratios, Tire Size, RPM
Limits and it will calculate a bunch of Stuff. Mainly
Shift points, MPH at RPM, and RPM Drop after a
gear change. Supports up to 6 speeds.

v0.2 Updated to fix some field validation bugs,
spelling, and error checks.
v0.5 Added Charts, better form, nicer look


For Just the Tire Size Calculator (TireCalc) Click
HERE