275/65R18 Tire Size in Inches and Millimeters

275/65R18 tires have a diameter of 32.1" (815 mm), a tread width of 10.8" (275 mm), and a wheel diameter of 18" (457.2 mm).The sidewall of the tire is 7" (179 mm), and the tire's circumference is 100.8" (2559.1 mm). This means a 275/65R18 tire will make make 629 revolutions per mile, or 391 revolutions per kilometer.

275/65R18 Tire Front
10.8"
32.1"
275/65R18 Tire Side
Tire Circumference
100.8"
18"
7"
629 Revs/Mile
SpecInchesMetric
Diameter32.1"815 mm
Width10.8"275 mm
Wheel18"457.2 mm
Sidewall7"179 mm
Circum100.8"2559.1 mm
Revolutions629 per mile391 per km

What Does 275/65R18 Mean?

The tire size 275/65R18 is a common size used on many trucks, SUVs, and other larger vehicles.

Here is what each part of the size designation represents:

  • 275: This number represents the width of the tire in millimeters. In this case, the tire is 275 millimeters wide.
  • 65: 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 65% 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.
  • 18: 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 18-inch wheel.

275/65R18 tire size meaning

How To Convert 275/65R18 Into Inches

The 275/65R18 conversion is fairly simple. The first number in the tire size, 275, represents the width of the tire in millimeters. To convert this to inches, we divide 275 by 25.4 (since there are 25.4 millimeters in an inch). This gives us approximately 10.8 inches.

The second number in the tire size, 65, represents the aspect ratio or the height of the tire as a percentage of its width. To calculate the height in inches, we multiply 10.8 by 0.65, which gives us approximately 7 inches.

Finally, the last number in the tire size, 18, represents the diameter of the wheel rim in inches. Therefore, the tire size 275/65R18 can be expressed in inches as roughly 10.8 inches wide, 7 inches tall, and designed to fit a 18-inch wheel rim.

Best 275/65R18 Tire
Starfire Solarus HT All-Season 275/65R18 116T Tire
4.6
$142.36

The Starfire Solarus HT All-Season 275/65R18 tire combines versatility and reliability to meet the demands of diverse driving conditions. Engineered with an all-season tread compound and optimized tread pattern, it delivers consistent traction and handling on both wet and dry surfaces. Whether you're commuting on highways or venturing off-road, the Starfire Solarus HT tire ensures a smooth, comfortable ride and dependable performance for your everyday journeys.

More Info
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03/17/2024 10:00 pm GMT

Frequently Asked Questions About 275/65R18 Tires

How tall is a 275/65R18 tire?

A 275/65R18 tire has an approximate height, also known as the overall diameter, of 32.1 inches (815 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 275/65R18 tire?

A 275/65R18 tire has a width of approximately 10.8 inches (275 millimeters). The width of the tire is the first number in the tire size designation, which in this case is “275”. 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 275/65R18 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
225/75R1831.3"795 mm18 mm
225/90R1632"812 mm16 mm
235/75R1831.9"809 mm18 mm
235/80R1731.8"808 mm17 mm
235/85R1631.7"806 mm16 mm
235/85R1732.8"832 mm17 mm
245/60R2031.6"802 mm20 mm
245/70R1831.5"801 mm18 mm
245/75R1731.5"800 mm17 mm
255/30R2632"814 mm26 mm
255/60R2032"814 mm20 mm
255/65R1932.1"815 mm19 mm
255/70R1832.1"815 mm18 mm
255/75R1732"814 mm17 mm
265/45R2231.4"797 mm22 mm
265/50R2232.5"825 mm22 mm
265/60R2032.5"826 mm20 mm
265/65R1831.5"801 mm18 mm
265/70R1731.7"804 mm17 mm
265/70R1832.6"829 mm18 mm
265/75R1631.7"804 mm16 mm
265/80R1632.7"830 mm16 mm
275/25R2631.4"798 mm26 mm
275/40R2331.7"804 mm23 mm
275/45R2231.8"807 mm22 mm
275/50R2131.9"809 mm21 mm
275/50R2232.9"835 mm22 mm
275/55R2031.9"810 mm20 mm
275/60R2033"838 mm20 mm
275/65R1832.1"815 mm18 mm
275/70R1631.2"792 mm16 mm
275/70R1732.2"818 mm17 mm
285/35R2431.9"810 mm24 mm
285/40R2332"812 mm23 mm
285/40R2433"838 mm24 mm
285/45R2232.1"815 mm22 mm
285/50R2031.3"794 mm20 mm
285/55R1931.4"797 mm19 mm
285/55R2032.4"822 mm20 mm
285/60R1831.5"799 mm18 mm
285/65R1731.6"802 mm17 mm
285/65R1832.6"827 mm18 mm
285/70R1631.7"806 mm16 mm
285/70R1732.8"832 mm17 mm
285/75R1632.8"834 mm16 mm
295/25R2631.8"808 mm26 mm
295/30R2633"838 mm26 mm
295/35R2432.1"816 mm24 mm
295/40R2231.3"795 mm22 mm
295/45R2232.5"825 mm22 mm
295/50R2031.7"804 mm20 mm
295/55R2032.8"832 mm20 mm
305/25R2632"812 mm26 mm
305/35R2331.4"798 mm23 mm
305/35R2432.4"824 mm24 mm
305/40R2231.6"803 mm22 mm
305/40R2332.6"828 mm23 mm
305/45R2232.8"833 mm22 mm
305/50R2032"814 mm20 mm
305/60R1731.4"798 mm17 mm
305/60R1832.4"823 mm18 mm
305/65R1732.6"828 mm17 mm
305/70R1531.9"809 mm15 mm
305/70R1632.8"834 mm16 mm
315/30R2431.5"800 mm24 mm
315/35R2432.7"830 mm24 mm
315/45R2132.2"817 mm21 mm
315/50R2032.4"824 mm20 mm
315/70R1532.4"823 mm15 mm
325/35R2332"812 mm23 mm
325/40R2131.2"793 mm21 mm
325/40R2232.2"819 mm22 mm
325/50R2032.8"834 mm20 mm
335/30R2432"812 mm24 mm
345/55R1732"812 mm17 mm
375/50R1832.8"833 mm18 mm
375/55R1632.2"818 mm16 mm
405/25R2432"812 mm24 mm