TireSizeCalc

265/65R18 tire size in inches

A 265/65R18 tire is 31.56 inches tall and 10.43 inches wide on a 18-inch rim. These are nominal dimensions from the official sizing formula.

Tire size information265/65R18
Dimension265/65R18 This size vs yours
Overall diameter
UN R30 §6.1.2.1
31.56 in 801.7 mm
Section width
UN R30 §6.1.2.1
10.43 in 265.0 mm
Sidewall height
UN R30 §6.1.2.1
6.78 in 172.3 mm
Rim diameter
Marked on the tire
18 in
Circum­ference
From diameter
99.16 in
Revolutions per mile
From diameter
639
Allowed real diameter
UN R30 §6.1.5
31.16–32.11 in
Nominal, not measuredReal tires vary by brand and load range.
265/60R1830.52 in265/65R1831.56 in265/70R1832.61 in
Drawn to scale on one ground line, with the next size down and up on the same rim. The dashed line marks the height of 265/65R18.

Is 265/65R18 a 32-inch tire?

Yes. At 31.56 inches tall, 265/65R18 is commonly called a 32-inch tire. Inch-class names round to the nearest inch; the true nominal height is 31.56 in, and a new tire may legally measure between 31.16 and 32.11 in.

See all 32-inch tire sizes.

Speedometer change

mphTrue speed 59.0 mph (−1.0 mph)

Example: if your speedometer is calibrated for 275/65R18 and you fit 265/65R18, the tire is −1.6% in diameter, so your true speed differs from the reading as shown below. Enter your current size above to see your own figures.

Speedometer reading versus true speed
ReadingTrue speedDifference
30 mph29.5 mph−0.5 mph
45 mph44.3 mph−0.7 mph
55 mph54.1 mph−0.9 mph
60 mph59.0 mph−1.0 mph
70 mph68.9 mph−1.1 mph
80 mph78.7 mph−1.3 mph

Sizes within 3% of 265/65R18

These sizes are within 3% of the diameter of 265/65R18. The 3% figure is a rule of thumb, not a regulation and not a fitment check: wheel width, offset, suspension and body clearance decide what fits. See changing tire size.

Sizes within 3% of 265/65R18
SizeDiameter (in)Width (in)Change ±3%Ride height (in)
265/75R1530.6510.43−2.9%−0.46
255/70R1731.0610.04−1.6%−0.25
245/75R1731.479.65−0.3%−0.05
265/65R1831.5610.43——
265/70R1731.6110.43+0.1%+0.02
265/75R1631.6510.43+0.3%+0.04
235/85R1631.739.25+0.5%+0.08
275/55R2031.9110.83+1.1%+0.17
255/75R1732.0610.04+1.6%+0.25
275/65R1832.0710.83+1.6%+0.26
275/70R1732.1610.83+1.9%+0.30
285/55R2032.3411.22+2.5%+0.39

Inch equivalent of 265/65R18

In inch terms, 265/65R18 is about 31.6x10.4R18: 31.6 in tall and 10.4 in wide, a 32-inch tire.

Nearest inch (flotation) sizes, same rim first. Diameter change is from 265/65R18.
Inch sizeDiameter (in)ChangeWidth (in)Dimensions from
33x12.50R1833.00+4.6%12.50numbers in the size
32x11.50R1531.54−0.1%11.42UN R54 table
33x12.50R1532.52+3.0%12.52UN R54 table
33x9.50R1532.52+3.0%9.45UN R54 table

How 265/65R18 is calculated

265 mm section width × 65% aspect ratio = 172.3 mm sidewall (6.78 in).

Overall diameter = rim + 2 × sidewall = 18 in + 2 × 6.78 in = 31.56 in.

Formula: UN Regulation No. 30 §2.15 and §6.1.2.1 (passenger) and UN Regulation No. 54 §6.1.2.1 (light truck). Revolutions per mile = 63,360 ÷ circumference. Full sources are listed at the end of this page.

Questions about 265/65R18

How tall is a 265/65R18 tire?
31.56 inches (801.7 mm) nominal. A new tire may measure from 31.16 to 32.11 in under the official tolerance; the maker's specification gives the figure for a specific tire.
How wide is a 265/65R18 tire?
10.43 inches (265.0 mm) section width. Overall width can be slightly larger; for passenger tires, US rule FMVSS 139 allows 7% over the specified width (or 10 mm, if larger, for some pressure classes).
How many revolutions per mile does 265/65R18 make?
About 639 nominal, from a circumference of 99.16 in. Tire makers publish measured revolutions per mile for each tire.
Will 265/65R18 fit my vehicle?
This page can't tell you. Check the tire size on your door-jamb placard, then confirm wheel width, offset and clearance with the tire or vehicle maker.

Related

Sources

This size is listed by the manufacturer: Goodyear Wrangler DuraTrac RT, checked on the manufacturer's site on 2026-11-01. The size page shows nominal figures, not that product's measurements.

  1. UN Regulation No. 30 - Uniform provisions concerning the approval of pneumatic tyres for motor vehicles and their trailers (Revision 3). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.29/Rev.3. 2007-03-29. Para 2.15 and 6.1.2.1: aspect ratio and outer diameter, D = d + 2H. Retrieved 2026-11-01.
  2. UN Regulation No. 54 - Uniform provisions concerning the approval of pneumatic tyres for commercial vehicles and their trailers (Revision 2). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.53/Rev.2. 2004-04-16. Para 6.1.2.1: the same formula for light truck tires. Retrieved 2026-11-01.
  3. UN Regulation No. 30 - Uniform provisions concerning the approval of pneumatic tyres for motor vehicles and their trailers (Revision 3). United Nations Economic Commission for Europe (UNECE). E/ECE/324 E/ECE/TRANS/505 Rev.1/Add.29/Rev.3. 2007-03-29. Para 6.1.5: allowed outer diameter, Dmin = d + 2H x 0.97, Dmax = d + 2H x 1.04. Retrieved 2026-11-01.
  4. Computed by tiresizecalc.net from the cited formula. Sri Murugan Systems. Circumference = pi x diameter; revolutions per mile = 63,360 / circumference; 1 in = 25.4 mm exactly. Retrieved 2026-11-01.
  5. 49 CFR 571.139 - Standard No. 139; New pneumatic radial tires for light vehicles. National Highway Traffic Safety Administration (NHTSA), Code of Federal Regulations (eCFR). 49 CFR 571.139. eCFR up to date as of 2026-10-15. S6.1.2: passenger tire width up to 7 percent (or 10 mm) over the specified width. Retrieved 2026-11-01.
  6. 49 CFR 571.110 - Standard No. 110; Tire selection and rims for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less. National Highway Traffic Safety Administration (NHTSA), Code of Federal Regulations, annual edition (GovInfo). 2006-10-01. S4.3: the door placard shows the original tire size. Retrieved 2026-11-01.

Last reviewed 2026-11-01. The full source list, with dates and file checksums, is in How the numbers are calculated. To report an error, email contactus@tiresizecalc.net.