265/55R18 Tire Size in Inches

29.5" tall, 10.4" wide, 5.7" sidewall

Diameter29.5"749 mm
Overall diameter29.5"749 mm
Section width10.4"265 mm
Sidewall height5.7"146 mm
Circumference92.6"2352 mm
Revolutions per mile684425 per km
Wheel diameter18"≈ 29.5x10.4R18 in inches

A 265/55R18 tire is 29.5 inches (749 mm) tall and 10.4 inches wide. The sidewall is 55% of the width, 5.7 inches, on a 18-inch wheel, and the tire turns about 684 times per mile.

In flotation terms that is about 29.5x10.4R18. People often call it a 29-inch tire.

The size most often compared with it is 285/50R18, which is 0.3" shorter (−0.9%). At an indicated 60 mph you would be doing 59.5 mph on it.

265/55R18
285/50R18
Diameter difference−0.87%diameter 29.48" → 29.22"
CurrentNew
CurrentNewDifference

Speedometer

ShowsActual speed

Gear ratio to match

–enter your current axle ratio

Sizes near 265/55R18

Same 18" wheel, within 20 mm of width and 10 points of aspect ratio.

SizeDiameterWidthSidewallvs 265/55R18
285/50R1829.2"11.2"5.6"−0.9%
275/55R1829.9"10.8"6.0"+1.5%
275/50R1828.8"10.8"5.4"−2.2%
285/55R1830.3"11.2"6.2"+2.9%
265/50R1828.4"10.4"5.2"−3.5%
245/65R1830.5"9.6"6.3"+3.6%
285/45R1828.1"11.2"5.0"−4.7%
255/50R1828.0"10.0"5.0"−4.9%
275/60R1831.0"10.8"6.5"+5.1%
275/45R1827.7"10.8"4.9"−5.9%

Same height on a different wheel

Sizes within 2% of 29.5" on 16" or 17" wheels.

SizeDiameterWidthSidewallvs 265/55R18
285/60R1629.5"11.2"6.7"−0.0%
245/70R1629.5"9.6"6.8"+0.1%
265/60R1729.5"10.4"6.3"+0.1%
215/80R1629.5"8.5"6.8"+0.2%
225/70R1729.4"8.9"6.2"−0.3%
315/50R1729.4"12.4"6.2"−0.3%

Speedometer with a different size

Actual speed when the speedometer is calibrated for 265/55R18.

Speedometer showson 285/50R18on 275/55R18on 275/50R18
30 mph29.7 mph30.4 mph29.3 mph
45 mph44.6 mph45.7 mph44.0 mph
60 mph59.5 mph60.9 mph58.7 mph
70 mph69.4 mph71.0 mph68.5 mph

265/55R18 FAQ

How tall is a 265/55R18 tire?

29.5 inches (749 mm). The sidewall is 5.7 inches.

How wide is a 265/55R18 tire?

10.4 inches (265 mm) section width, measured sidewall to sidewall.

What is 265/55R18 in flotation size?

About 29.5x10.4R18.

Can I use 285/50R18 instead of 265/55R18?

285/50R18 is −0.9% in diameter, within the common 3% guideline. It is 0.8" wider.