315/20R30 Tire Size in Inches and Millimeters

315/20R30 tires have a diameter of 35" (888 mm), a tread width of 12.4" (315 mm), and a wheel diameter of 30" (762 mm).The sidewall of the tire is 2.5" (63 mm), and the tire's circumference is 109.9" (2788.3 mm). This means a 315/20R30 tire will make make 577 revolutions per mile, or 359 revolutions per kilometer.

315/20R30 Tire Front
12.4"
35"
315/20R30 Tire Side
Tire Circumference
109.9"
30"
2.5"
577 Revs/Mile
SpecInchesMetric
Diameter35"888 mm
Width12.4"315 mm
Wheel30"762 mm
Sidewall2.5"63 mm
Circum109.9"2788.3 mm
Revolutions577 per mile359 per km

What Does 315/20R30 Mean?

The tire size 315/20R30 is a common size used on many trucks, SUVs, and other larger vehicles.

Here is what each part of the size designation represents:

  • 315: This number represents the width of the tire in millimeters. In this case, the tire is 315 millimeters wide.
  • 20: This number represents the aspect ratio of the tire, which is the height of the tire's sidewall as a percentage of its width. In this case, the sidewall height is 20% of the tire's width.
  • R: This letter indicates the tire's construction type. “R” stands for radial construction, which is the most common type of tire construction today.
  • 30: This number represents the diameter of the wheel that the tire is designed to fit on, in inches. In this case, the tire is designed to fit on a 30-inch wheel.

315/20R30 tire size meaning

How To Convert 315/20R30 Into Inches

The 315/20R30 conversion is fairly simple. The first number in the tire size, 315, represents the width of the tire in millimeters. To convert this to inches, we divide 315 by 25.4 (since there are 25.4 millimeters in an inch). This gives us approximately 12.4 inches.

The second number in the tire size, 20, represents the aspect ratio or the height of the tire as a percentage of its width. To calculate the height in inches, we multiply 12.4 by 0.20, which gives us approximately 2.5 inches.

Finally, the last number in the tire size, 30, represents the diameter of the wheel rim in inches. Therefore, the tire size 315/20R30 can be expressed in inches as roughly 12.4 inches wide, 2.5 inches tall, and designed to fit a 30-inch wheel rim.

Frequently Asked Questions About 315/20R30 Tires

How tall is a 315/20R30 tire?

A 315/20R30 tire has an approximate height, also known as the overall diameter, of 35 inches (888 mm). This height can vary slightly depending on the brand and model of the tire, as well as the amount of air pressure in the tire.

How wide is a 315/20R30 tire?

A 315/20R30 tire has a width of approximately 12.4 inches (315 millimeters). The width of the tire is the first number in the tire size designation, which in this case is “315”. It’s important to note that the actual width of the tire may vary slightly depending on the brand and model of the tire, and the width may also be affected by the amount of air pressure in the tire.

Alternate 315/20R30 Replacement Tire Sizes

Upsizing your wheels or tires? Replacement tires must be within 3% of the diametor of the original tire. The following sizes fall within that range - click on any size to see detailed info about that tire and wheel combination.

SizeDiameterWidthWheel
275/25R3035.4"900 mm30 mm
275/65R2034.1"866 mm20 mm
275/80R1734.3"872 mm17 mm
275/80R1835.3"897 mm18 mm
285/55R2234.4"873 mm22 mm
285/65R2034.6"878 mm20 mm
285/75R1834.8"885 mm18 mm
295/45R2434.5"876 mm24 mm
295/55R2234.8"883 mm22 mm
295/60R2033.9"862 mm20 mm
295/65R2035.1"892 mm20 mm
295/70R1834.3"871 mm18 mm
295/75R1734.4"874 mm17 mm
305/35R2634.4"874 mm26 mm
305/45R2434.8"884 mm24 mm
305/50R2234.1"865 mm22 mm
305/55R2235.2"895 mm22 mm
305/60R2034.4"874 mm20 mm
305/70R1834.8"885 mm18 mm
305/75R1634"864 mm16 mm
315/20R3035"888 mm30 mm
315/40R2534.9"887 mm25 mm
315/40R2635.9"912 mm26 mm
315/45R2435.2"894 mm24 mm
315/50R2234.4"875 mm22 mm
315/60R2034.9"886 mm20 mm
315/70R1734.4"874 mm17 mm
315/70R1835.4"899 mm18 mm
315/75R1634.6"878 mm16 mm
325/45R2435.5"902 mm24 mm
325/50R2234.8"885 mm22 mm
325/60R2035.4"898 mm20 mm
325/65R1834.6"879 mm18 mm
325/70R1735"888 mm17 mm
335/35R2635.2"894 mm26 mm
335/40R2434.6"878 mm24 mm
335/55R2034.5"876 mm20 mm
335/70R1634.5"876 mm16 mm
345/60R1834.3"871 mm18 mm
355/40R2435.2"894 mm24 mm
355/50R2034"864 mm20 mm
355/70R1635.6"904 mm16 mm
375/40R2435.8"910 mm24 mm
375/45R2235.3"897 mm22 mm
375/60R1835.7"907 mm18 mm
375/65R1635.2"894 mm16 mm
385/35R2434.6"880 mm24 mm