tire size

I have just purchased a set of ADR (18 X 8.5) rims for my 99' Silverado. Does anyone know of a calculator or chart that I can use to size up some rubber for this size rim? I think I want to go with a 245/45/18. Any help would be greatly appreciated.

Maybe try www.tirerack.com (http://www.tirerack.com) That might have some info for you to use.

sidewall is percentage of tread width. So a 245/45 would have a tread width of 245 mm and a sidewall of (245 x .45) or 110.25 mm. Know move decimal one place to the right to change mm to cm and multiply by .3937 to convert to inches. so the sidewall is 4.34 inches. total size would be 18 + (4.34x2)8.68 or 26.68 inches tall. this isn't exact with the size charts but it will get you close enough to guestimate fit.

If your truck is stock, you can defiantely run those tires.

my truck is @ stock ride height now but I am looking to drop it down 2/4 or 3/4 in the near future. should i go with a smaller tire if i am going to lower it? factory tire size is 255/70/16. 30.05" in total diameter. after looking @ the chart @ tirerack.com i want to go with a 255/45/18. will i have clearance problems?

my truck is @ stock ride height now but I am looking to drop it down 2/4 or 3/4 in the near future. should i go with a smaller tire if i am going to lower it? factory tire size is 255/70/16. 30.05" in total diameter. after looking @ the chart @ tirerack.com i want to go with a 255/45/18. will i have clearance problems?
Going 2/4 you can definately run the 255/45/18, but not at 3/4. My roomate has 4/6(*cough*poser*cough*) and runs a 245/40/18. But they're too small. I'm think 245/45 would probably be good at 3/4, but if 2/4 then go a little bigger. Just my suggestion.

thanks for the advice. i'll post when i get it together and let you know how i made out.