tireheight.com

255/60R18 in inches

A 255/60R18 tire is 30.0″ tall and 10.0″ wide, and fits a 18″ wheel. In inches it is written 30.0×10.0R18.

Diameter30.05″
Width10.04″
Sidewall6.02″
255/60R18 drawn to scale: 30.05 inch diameter, 6.02 inch sidewall, 18 inch wheel, 10.04 inch tread width18″ wheel6.02″30.05″ overall10.04″ wideSide view
Drawn to scale. Nominal dimensions calculated from the size code.
Manufacturer data

How tall 255/60R18 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 14 tires in this size. Their published revolutions per mile work out to 29.1–29.2″ under load (below).

Real 255/60R18 tires measure 30.00–30.04″, against 30.05″ from the size code. They run both taller and shorter than the size code.

Height under load29.1–29.2″

Published revs per mile (691–692) mean the tire rolls like a 29.1–29.2″ tire on the vehicle. Use this for speedometer calibration.

Weight spread31.6–38.0 lb

The lightest (General G-MAX Justice, XL) is 6.4 lb lighter per corner than the heaviest (Toyo Open Country A/T III, XL).

14 tires in 255/60R18

Sort by the spec you care about.

LoadRevs/miSource
General G-MAX JusticePerformanceXL · 112V30.0031.610.02,469691Spec page
General G-MAX Justice AWAll-weatherXL · 112V30.0031.611.02,469691Spec page
Michelin CrossClimate2All-seasonXL · 112V30.0032.210.02,469692Spec page
Michelin Pilot Sport 4 SUVPerformanceXL · 112W30.0032.39.52,469692Spec page
Michelin Defender2All-seasonXL · 112V30.0433.610.52,469692Spec page
Toyo Celsius SportPerformanceXL · 112W30.0433.710.72,469692Spec page
Michelin X-Ice SnowWinterXL · 112T30.0433.910.52,469692Spec page
Toyo Proxes ST IIIPerformanceXL · 112V30.0435.710.12,469692Spec page
BFGoodrich Advantage ControlAll-seasonXL · 112V30.0435.910.52,469692Spec page
Toyo Proxes G-TourXL · 112V30.0036.29.72,469692Spec page
Toyo OPEN COUNTRY Q/TAll-seasonXL · 112V30.0437.012.22,469692Spec page
Toyo Observe G3-IceWinterXL · 112T30.0437.313.12,469692Spec page
BFGoodrich Elite-Force T/AAll-seasonXL · 112V30.0437.610.52,469692Spec page
Toyo Open Country A/T IIIAll-terrainXL · 112T30.0438.013.22,469692Spec page

Is 255/60R18 a 30-inch tire?

≈30″

Yes. The size code works out to 30.05″, and the 14 tires here publish 30.00–30.04″, so people call it a 30.

All 30-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

SizeDiameter ″vs 255/60R18Difference
235/60R1829.10-0.94″-3.1%
245/60R1829.57-0.47″-1.6%
235/70R1729.95-0.09″-0.3%
275/60R1729.99-0.06″-0.2%
235/65R1830.03-0.02″-0.1%
255/55R1930.04-0.00″-0.0%
255/65R1730.05+0.00″+0.0%
235/60R1930.10+0.06″+0.2%
265/60R1830.52+0.47″+1.6%
275/60R1830.99+0.94″+3.1%

How to read 255/60R18

How to read any tire size

255/60R18 112V as printed on the tire sidewall, with each part numbered255/60R18 112V123456
How 255/60R18 112V is printed on the sidewall. It's the most common code among the 14 tires here (9 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

260Aspect ratio

A percentage, not a measurement: the sidewall is 60% as tall as the tire is wide, which is 153.0 mm or 6.02 inches.

3RConstruction

Radial construction.

418Wheel diameter

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

5112Load index

Each tire carries up to 2,469 lb (1,120 kg) at its maximum pressure.

6VSpeed rating

Rated for up to 149 mph sustained.

XLExtra load

Printed after the size.

SpecificationInchesMetric
Overall diameter30.05763 mm
Section width10.04255 mm
Sidewall height6.02153.0 mm
Circumference94.42,398 mm
Revolutions per mile (calculated, unloaded)671.2417 per km
Revolutions per mile (published by manufacturers)691–692429–430 per km
Approved wheel width7.0–9.0178–229 mm

Speedometer error after switching to 255/60R18

Your actual speed– mph

Questions about 255/60R18

What is 255/60R18 in inches?

30.05 inches tall, 10.04 inches wide, on a 18-inch wheel. Written in inches, that is roughly 30.0×10.0R18.

How much does a 255/60R18 tire weigh?

Between 31.6 lb and 38.0 lb for the 14 tires listed here. The lightest is the General G-MAX Justice (XL); the heaviest is the Toyo Open Country A/T III (XL).

What wheel width do I need for 255/60R18?

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

How many revolutions per mile does a 255/60R18 make?

Published figures run 691–692 revolutions per mile. The calculated figure is 671.2, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 255/60R18 than 235/65R18?

0.02 inches taller on paper (30.05″ vs 30.03″), which raises the axle about 0.01″. Your speedometer will read about 0.1% slow.