i hope this is the right place to post this. if not i am sorry. i am getting a custom made chip for my car. they are asking for the tire size and Dia. i don't know what the dia. is. i have 245/50/16 tires on iroc wheels. could anyone please help me. thanks for any info.

 

According to this site tire calculator diameter is 25.6 inch

 

If you ever have the need to calculate the wheel and tire diameter
but don't have the tire calculator site available here is the
equation.

2 x ((tire width x aspect ratio)/25.4) + Wheel Diameter

example of 245/50/16 (tire width/aspect ratio/wheel diameter)

tire width = 245mm
aspect ratio = 50% of width = 50/100 = 0.5
wheel diameter = 16 inches

2 x ((245 x 0.5)/25.4) + 16 = 25.64

 

thanks for the help