Tires: diameter of tire, tire size calculator, general tire

Question
what is the diameter of a 225/75R 17 General Tire?

Answer
Duane,

Here's a tire size calculator:

http://www.1010tires.com/TireSizeCalculator.asp

But this calculator assumes that the tire made EXACTLY to those dimensions.  There may be a small amount of difference, so to be sure that is was you need to ask the tire manufacturer - and you have to be specific about the model as there may be slight differences between models.