tireheight.com

255/65R18 in inches

A 255/65R18 tire is 31.1″ tall and 10.0″ wide, and fits a 18″ wheel. In inches it is written 31.1×10.0R18.

Diameter31.05″
Width10.04″
Sidewall6.53″
255/65R18 drawn to scale: 31.05 inch diameter, 6.53 inch sidewall, 18 inch wheel, 10.04 inch tread width18″ wheel6.53″31.05″ overall10.04″ wideSide view
Drawn to scale. Nominal dimensions calculated from the size code.
Manufacturer data

How tall 255/65R18 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 16 tires in this size. Their published revolutions per mile work out to 30.1–30.2″ under load (below).

Real 255/65R18 tires measure 31.00–31.10″, against 31.05″ from the size code. They run both taller and shorter than the size code.

Height under load30.1–30.2″

Published revs per mile (669–670) mean the tire rolls like a 30.1–30.2″ tire on the vehicle. Use this for speedometer calibration.

Weight spread32.7–47.6 lb

The lightest (Michelin Primacy All Season, SL) is 14.9 lb lighter per corner than the heaviest (Toyo Open Country H/T II, LT E).

16 tires in 255/65R18

Sort by the spec you care about.

LoadRevs/miSource
Michelin Primacy All SeasonTouringSL · 111H31.1032.78.52,403670Spec page
Michelin CrossClimate2All-seasonSL · 111H31.0033.510.02,403670Spec page
Michelin Defender2All-seasonSL · 111H31.0034.410.52,403670Spec page
Toyo Celsius IITouringSL · 111H31.0634.411.82,403669Spec page
Michelin X-Ice SnowWinterSL · 111T31.0635.410.52,403670Spec page
General Grabber Arctic XWinterXL · 115T31.1035.512.02,679669Spec page
Michelin X-Ice Snow+WinterXL · 115H31.0635.610.52,679670Spec page
General Grabber H/THighwaySL · 111T31.1036.912.02,403669Spec page
Toyo Open Country H/T IIHighwaySL · 111T31.0637.811.82,403669Spec page
BFGoodrich Advantage Control HTHighwaySL · 111T31.0638.012.02,403670Spec page
General Grabber H/THighwaySL · 111H31.1038.512.02,403669Spec page
Toyo OPEN COUNTRY Q/TAll-seasonSL · 109S31.0639.312.72,271669Spec page
BFGoodrich Trail-Terrain T/AAll-terrainSL · 111T31.1042.412.52,403670Spec page
BFGoodrich Trail-Terrain T/A+SL · 111T31.1043.012.52,403670Spec page
Michelin Defender LTX M/SAll-seasonLT E · 120/117R31.0044.213.53,085670Spec page
Toyo Open Country H/T IIHighwayLT E · 120/117R31.0647.614.23,085669Spec page

Is 255/65R18 a 31-inch tire?

≈31″

Yes. The size code works out to 31.05″, and the 16 tires here publish 31.00–31.10″, so people call it a 31.

All 31-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

SizeDiameter ″vs 255/65R18Difference
265/60R1830.52-0.53″-1.7%
235/75R1730.88-0.17″-0.6%
275/55R1930.91-0.14″-0.5%
275/60R1830.99-0.06″-0.2%
255/60R1931.05-0.00″-0.0%
255/70R1731.06+0.00″+0.0%
275/65R1731.07+0.02″+0.1%
285/60R1831.46+0.41″+1.3%
245/70R1831.50+0.45″+1.5%
265/65R1831.56+0.51″+1.6%

How to read 255/65R18

How to read any tire size

255/65R18 111T as printed on the tire sidewall, with each part numbered255/65R18 111T123456
How 255/65R18 111T is printed on the sidewall. It's the most common code among the 16 tires here (6 of them); tires in this size come in other load and speed ratings too.
1255Section width

255 mm across the widest point, or 10.04 inches. Every 255 size

265Aspect ratio

A percentage, not a measurement: the sidewall is 65% as tall as the tire is wide, which is 165.8 mm or 6.53 inches.

3RConstruction

Radial construction.

418Wheel diameter

Mounts on a 18-inch wheel. Approved wheel widths run 7.0″ to 9.0″.

5111Load index

Each tire carries up to 2,403 lb (1,090 kg) at its maximum pressure.

6TSpeed rating

Rated for up to 118 mph sustained.

SpecificationInchesMetric
Overall diameter31.05789 mm
Section width10.04255 mm
Sidewall height6.53165.8 mm
Circumference97.62,478 mm
Revolutions per mile (calculated, unloaded)649.5404 per km
Revolutions per mile (published by manufacturers)669–670416 per km
Approved wheel width7.0–9.0178–229 mm

Speedometer error after switching to 255/65R18

Your actual speed– mph

Questions about 255/65R18

What is 255/65R18 in inches?

31.05 inches tall, 10.04 inches wide, on a 18-inch wheel. Written in inches, that is roughly 31.1×10.0R18.

How much does a 255/65R18 tire weigh?

Between 32.7 lb and 47.6 lb for the 16 tires listed here. The lightest is the Michelin Primacy All Season (SL); the heaviest is the Toyo Open Country H/T II (LT E).

What wheel width do I need for 255/65R18?

Manufacturers approve 7.0–9.0″ wide wheels for this size.

How many revolutions per mile does a 255/65R18 make?

Published figures run 669–670 revolutions per mile. The calculated figure is 649.5, but manufacturers measure the tire under load, where it rolls on a smaller radius.

What is the difference between P255/65R18 and LT255/65R18?

Passenger tires (14 here) are built for passenger loads, with max loads of 2271–2679 lb. Light-truck tires (2 here) come in heavier load ranges with max loads of 3085 lb, and are usually heavier with deeper tread.

How much taller is 255/65R18 than 275/60R18?

0.06 inches taller on paper (31.05″ vs 30.99″), which raises the axle about 0.03″. Your speedometer will read about 0.2% slow.