RPM -> MPH Mostly just a fun toy but also helpful in choosing transmission gearing, axle ratio and tires sizes. This calculator will give you your speed in MPH at a range of RPM's from 1000 - 7000 in 200 and 500 rpm increments.   T5 Driven Gear Installed a T5 and now your speedometer is off? This is the calc for you. Enter your driven gear, tire size, and axle ratio to find out exactly which gear you need for the end of your speedometer cable.   T5 ID / Info If you have a T5 and know the Borg Warner number from it or the year/car/model it is from this calc will give you the gear ratios and any technical info I have on it.   Tire Sizing A good calc for figuring out +1 or +2 tire sizing, dual calcs for doing easy comparasins. Calculates width, diameter, sidewall height and circumfrence all in inches. Also calculates the same measurements but as a difference between the two sizes.   Miscellaneous Calculators Miscellaneous calcs include a temperature conversion (fahrenheit <-> elcious) and an eCommerce Bullshit Generator (good laughs for you corporate and IT guys).   Resistor ID Set the resistor band color code and get back the resistance value.