tireheight.com

215/55R18 in inches

A 215/55R18 tire is 27.3″ tall and 8.5″ wide, and fits a 18″ wheel. In inches it is written 27.3×8.5R18.

Diameter27.31″
Width8.46″
Sidewall4.66″
215/55R18 drawn to scale: 27.31 inch diameter, 4.66 inch sidewall, 18 inch wheel, 8.46 inch tread width18″ wheel4.66″27.31″ overall8.46″ wideSide view
Drawn to scale. Nominal dimensions calculated from the size code.
Manufacturer data

How tall 215/55R18 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 11 tires in this size. Their published revolutions per mile work out to 26.5″ under load (below).

Real 215/55R18 tires measure 27.20–27.30″, against 27.31″ from the size code. They run both taller and shorter than the size code.

  1. General AltiMAX Arctic X27.30″ −0.01″
  2. General AltiMAX RT45 · 227.30″ −0.01″
  3. Michelin CrossClimate227.30″ −0.01″
  4. Toyo Extensa A/S II27.28″ −0.03″
  5. Toyo Observe G3-Ice27.28″ −0.03″
  6. BFGoodrich Advantage Control27.28″ −0.03″
  7. Michelin X-Ice Snow27.28″ −0.03″
  8. Michelin X-Ice Snow+27.28″ −0.03″
  9. Toyo Proxes G-Tour27.28″ −0.03″
  10. Michelin Defender227.20″ −0.11″
Each bar runs from the size code's 27.31″ (the orange line) to the model's published height. The track spans 1.0″. Where a model comes in several load ranges, the darker part shows its range of heights; the number after the name is how many versions it comes in.
Height under load26.5″

Published revs per mile (761–762) mean the tire rolls like a 26.5″ tire on the vehicle. Use this for speedometer calibration.

Weight spread23.6–27.6 lb

The lightest (General AltiMAX RT45, SL) is 4.0 lb lighter per corner than the heaviest (Toyo Observe G3-Ice, XL).

11 tires in 215/55R18

Sort by the spec you care about.

LoadRevs/miSource
General AltiMAX RT45TouringSL · 95T27.3023.611.01,521761Spec page
General AltiMAX RT45TouringSL · 95H27.3023.611.01,521761Spec page
Michelin Defender2All-seasonSL · 95H27.2024.610.51,521762Spec page
Toyo Extensa A/S IIAll-seasonXL · 99V27.2824.710.51,709761Spec page
Michelin CrossClimate2All-seasonSL · 95H27.3025.010.01,521762Spec page
BFGoodrich Advantage ControlAll-seasonSL · 95H27.2825.311.51,521762Spec page
General AltiMAX Arctic XWinterXL · 99T27.3025.812.01,709761Spec page
Michelin X-Ice Snow+WinterXL · 99H27.2825.810.51,709762Spec page
Michelin X-Ice SnowWinterXL · 99H27.2826.110.51,709762Spec page
Toyo Proxes G-TourXL · 99H27.2827.111.61,709761Spec page
Toyo Observe G3-IceWinterXL · 99T27.2827.612.01,709761Spec page

Is 215/55R18 a 27-inch tire?

≈27″

Yes. The size code works out to 27.31″, and the 11 tires here publish 27.20–27.30″, so people call it a 27.

All 27-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

SizeDiameter ″vs 215/55R18Difference
245/45R1826.68-0.63″-2.3%
315/35R1826.68-0.63″-2.3%
225/50R1826.86-0.45″-1.7%
285/40R1826.98-0.33″-1.2%
255/45R1827.04-0.28″-1.0%
235/50R1827.25-0.06″-0.2%
265/45R1827.39+0.08″+0.3%
345/35R1827.51+0.20″+0.7%
245/50R1827.65+0.33″+1.2%
225/55R1827.74+0.43″+1.6%

How to read 215/55R18

How to read any tire size

215/55R18 95H as printed on the tire sidewall, with each part numbered215/55R18 95H123456
How 215/55R18 95H is printed on the sidewall. It's the most common code among the 11 tires here (4 of them); tires in this size come in other load and speed ratings too.
1215Section width

215 mm across the widest point, or 8.46 inches. Every 215 size

255Aspect ratio

A percentage, not a measurement: the sidewall is 55% as tall as the tire is wide, which is 118.3 mm or 4.66 inches.

3RConstruction

Radial construction.

418Wheel diameter

Mounts on a 18-inch wheel. Approved wheel widths run 6.0″ to 7.5″.

595Load index

Each tire carries up to 1,521 lb (690 kg) at its maximum pressure.

6HSpeed rating

Rated for up to 130 mph sustained.

SpecificationInchesMetric
Overall diameter27.31694 mm
Section width8.46215 mm
Sidewall height4.66118.3 mm
Circumference85.82,179 mm
Revolutions per mile (calculated, unloaded)738.5459 per km
Revolutions per mile (published by manufacturers)761–762473 per km
Approved wheel width6.0–7.5152–191 mm

Speedometer error after switching to 215/55R18

Your actual speed– mph

Questions about 215/55R18

What is 215/55R18 in inches?

27.31 inches tall, 8.46 inches wide, on a 18-inch wheel. Written in inches, that is roughly 27.3×8.5R18.

How much does a 215/55R18 tire weigh?

Between 23.6 lb and 27.6 lb for the 11 tires listed here. The lightest is the General AltiMAX RT45 (SL); the heaviest is the Toyo Observe G3-Ice (XL).

What wheel width do I need for 215/55R18?

Manufacturers approve 6.0–7.5″ wide wheels for this size.

How many revolutions per mile does a 215/55R18 make?

Published figures run 761–762 revolutions per mile. The calculated figure is 738.5, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 215/55R18 than 235/50R18?

0.06 inches taller on paper (27.31″ vs 27.25″), which raises the axle about 0.03″. Your speedometer will read about 0.2% slow.