Typical P-Metric Format Specs:
 (Your tire size may not be listed)
155/70R12     165/60-13
175-70-14 91S 175/75R13XL
P185/60R15    P185/65R14
P185/70-14    P185-75-14
P195/50ZR16   P195/55R15
P195/65R15    P195/75R15
205-55-16     205-60-15 98M
P205/75R17    P215/70R16
215/55ZR16    ST215-60-16XL
P225/50-17    P225/55R16
225-60R16 92S P225/70-14
LT225/60R17   LT225/65ZR16
ST225-60R16   P225/70-14
235/65-17 XL  P235-70R16
LT235/85R16   245/35ZR19
P245/70-16    LT245/75R16
255-40ZR18    P255/45-19
P255/50R20    LT255/70R16
265/35ZR18    P265/50R20
P265/70-17    P265-75-16XL
275-40ZR18XL  275/40ZR19
LT275/65R18   LT275/65R20
285/30ZR21    285/35ZR17
285/35ZR22    ST285/40R18
LT285/70-17   295/35ZR18
305-45R22     LT305/60-20
LT315/70R16   355/35R20
Car / SUV / Van / Light Truck Tire Calculator (P-metric)
Enter 1 or 2 tire sizes!  ( For calculations, P205/65R15, 205-65-15 and LT205/65ZR15 are same size. )
* Auto Manufacturer's Suggested Tire Size

1 Type in the old P-metric tire size:

Click

CALCULATED:
Overall Wheel diameter in Inches
Wheel Circumference in Inches
Wheel revolutions per mile
Wheel revolutions per second @ 65MPH
* ALTERNATE or Desired Tire Size

2 Type in the new P-metric tire size:

Click

CALCULATED:
Overall Wheel diameter in Inches
Wheel Circumference in Inches
Wheel revolutions per mile
Wheel revolutions per second @ 65MPH
NOTE: Changing the tire diameter CHANGES the SPEEDOMETER accuracy!

This ALTERNATE tire size will cause the 'Actual Vehicle Speed' to be

mph, when the speedometer reads exactly 65mph.

Or, when the 'Actual Vehicle Speed' is 65mph the speedometer will now read

Also, the ground clearance of the vehicle will change by inches.


Print this page for your records. Bookmark this page on your browser.
* It is possible to specify non-existent tire sizes. The original manufacturer's suggested tire size may
be found in the owner's manual or on the edge of the open driver's door or door jamb or glove box.
MM = millimeters metric system, 25.4 mm = 1 inch exactly.

Web page created by Jim Shook 09/03/2003, last updated 03/15/2006
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