Please leave the troublesome calculation of wheel tire change to Tire Calculator! [Function] ① Wheel offset calculation (select rim width and offset or backspace) · Inner and outer rim position change amount (inch or mm) · Rim width change (inch or mm) · Change amount of tread (inch or mm) ② Speedometer error calculation (Select tire size or directly input outer diameter) Automatic calculation of tire outer diameter before and after replacement · Speed error(%) Real speed to meter display · Actual speed at 40(mph or km/h) display *40 can be changed · Actual travel distance when traveling 1000 (mile or km) distance · Change in vehicle height (inch or mm) *The error of the car can also be added to the speed error calculation ③ Speedometer error measurement (GPS use) Actually run the vehicle, compare the GPS measurement value with the speedometer and measure the error *Results will cause errors depending on the measurement environment. [Features] · Easy-to-understand screen design! · Simple and easy operation! [Specification] Settable range ○ Offset calculation · Rim width 3.5 J to 16 J · offset (mm) -60 to +70 · backspace (in) 3" to 13" ○ Speed error calculation · Tire width (mm) 135 to 405 · Profile (%) 20 to 85,82(R) · Wheel diameter (inch) 10 to 32 · Tire outer diameter direct input range 100 to 2000(mm) or 5-100(inch) · Vehicle side error correction (%) -30 to +30 ○ Speedometer error measurement · Measurable speed (km / h or mph) 10 ~ 300 [Notes] An error arises in the calculation result depending on the wheel brand and the brand of the tire. Be sure to consult experts before actually changing the specifications. Application creator assumes absolutely no responsibility.