Converting the XXX\XX\XX into actual inch numbers.

Reply Subscribe

Thread Tools

Search this Thread

May 7, 2008 | 11:35 AM

RCTrucker7

Thread Starter

Senior Member

Joined: Dec 2005

Posts: 544

From: Springfield, VA

Converting the XXX\XX\XX into actual inch numbers.

How do you do this?

Ex; 275/40/17 would convert to what in diameter and width, and how do you convert it?

May 7, 2008 | 11:58 AM

tsumi88

THE ONLY DARK GREEN VERT

Joined: Jan 2008

Posts: 466

From: denver

ive always used
http://www.miata.net/garage/tirecalc.html
hope this helps

May 7, 2008 | 12:04 PM

96TangerineBossGT

Senior Member

Joined: Aug 2005

Posts: 466

From: NC

Quote:

Originally Posted by RCTrucker7

How do you do this?

Ex; 275/40/17 would convert to what in diameter and width, and how do you convert it?

The 275 is the width of the tire in millimeters, in this case it equals 27.5 centimeters.

The 40 is the aspect ratio, as in the sidewall height of the tire is 40% of the width. Therefore, that tire would have a sidewall height of 110 millimeters or 11 centimeters.

The 17 is the diameter in inches.

1 inch = 2.54 centimeters, 1 centimeter ~ .3937 inch (1/2.54)

Scott