Gear & Tire Calculator
What Do You Need to Calculate?
How the Calculator Works
This calculator can be used to either calculate your gear ratio or your ideal cruising RPM at 65 MPH given a specific gear ratio input. Start by entering your tire diameter in inches or your rigs current gear ratio. Like magic, we instantly display what cruising RPM your setup will yield or the gear ratio you need to get your rig rollin’ right.
Put away those cumbersome gear ratio charts. Our easy to use calculator gives you a wealth of information when searching for your rig’s best gearing—3 recommended gear ratios! Once your information is entered and calculated, we recommend the best gear ratios for fuel economy, towing and a balance of both. Keep in mind, our calculator is based around a 1:1 transmission gear ratio or "direct drive". Essentially, this is your engine and the driveshaft behind the transmission spinning at the same speed.