Need to compute gear ratios for an appropriate vehicle speed? Use this form to calculate your vehicle speed (approx.) Unfortunately designed for Microsoft Internet Explorer Note: Tire size assumes that a 35" tire is exactly 35" in diameter. Tread wear / over inflation will effect actual size under extreme conditions. Also, a balloon factor will effect size at high velocities, so use this as a close approximation. Established Final Drive Ratio Engine Speed (RPM) Tire Size (in) Final Drive Ratio Your Vehicle Speed is:  MPH ... or   Hours per Mile Previous Speed #1:  MPH ... or   Hours per Mile Previous Speed #2:  MPH ... or   Hours per Mile More Specific Final Drive Ratio Engine Speed (RPM) Tire Size (in) Transmission Gear Ratio: Crawl Box #1: Crawl Box #2: Transfercase: Ring & Pinion Ratio: Your Vehicle Speed is:  MPH ... or   Hours per Mile Previous Speed #1:  MPH ... or   Hours per Mile Previous Speed #2:  MPH ... or   Hours per Mile Crawl Ratio Calculator How do I determine what ratios I have? Table of most common Toyota Crawl Ratios Toyota 4WD First Gear Transmission Ratios Close this window