mathematical equation for calculating rolling diamiter of a wheel+tire

[DecoyOctopus]

anyone know?

[DecoyOctopus]

lol just kiddn

google is my friend

[yogi08]

no... google owned you in the face with kak

[redrumracer]

its not that hard to have figured out if you knew the formula for pi

[stillaneon]

its not that hard to have figured out if you knew the formula for pi

the formula for pi??

Pi is a number... = 3.14159265

[Kaiser]

It has nothing to do with Pi. Diameters are straight lines.

Example: 16" wheel, 205/45R16 tire.

(((205*.45)x2)+(16x25.4))/25.4= Rolling Diameter of Tire/Wheel combo in Inches.

24.12 inches, for that example.

[Init2winit]

Do you want to know tire height, or run out?

[Kaiser]

The question he asked was rolling diameter. Not Tire Height nor run-out. The equation I gave will always give you the distance between the two furthest points in a tire without having to worry about figuring anything extra out, it works off of just what you already know with the tire and wheel sizes, and is what most tire shops use to figure out what size tires you can throw on a vehicle without penalty. Stock rolling diameter give or take a half inch either way is all most shops will do.

[DecoyOctopus]

winner

The question he asked was rolling diameter. Not Tire Height nor run-out. The equation I gave will always give you the distance between the two furthest points in a tire without having to worry about figuring anything extra out, it works off of just what you already know with the tire and wheel sizes, and is what most tire shops use to figure out what size tires you can throw on a vehicle without penalty. Stock rolling diameter give or take a half inch either way is all most shops will do.

[redrumracer]

the formula for pi??

Pi is a number... = 3.14159265

22/7

circumference divide by diameter

[Init2winit]

The question he asked was rolling diameter. Not Tire Height nor run-out. The equation I gave will always give you the distance between the two furthest points in a tire without having to worry about figuring anything extra out, it works off of just what you already know with the tire and wheel sizes, and is what most tire shops use to figure out what size tires you can throw on a vehicle without penalty. Stock rolling diameter give or take a half inch either way is all most shops will do.

Your math equation is only accurate if the tire is exactly what the given dimensions are. Most tires are not. There can be as much as 1/2" difference in circumference in a tire. No math problem here, you'll just have to do it the old fashioned way if you want an exact measurement. I'm not sure how exact he wants to be. If he wants a generalization, then that will work fine. If he wants exact measurements, that will not work.