tireheight.com

245/50R18 in inches

A 245/50R18 tire is 27.6″ tall and 9.6″ wide, and fits a 18″ wheel. In inches it is written 27.6×9.6R18.

Diameter27.65″
Width9.65″
Sidewall4.82″
245/50R18 drawn to scale: 27.65 inch diameter, 4.82 inch sidewall, 18 inch wheel, 9.65 inch tread width18″ wheel4.82″27.65″ overall9.65″ wideSide view
Drawn to scale. Nominal dimensions calculated from the size code.
Manufacturer data

How tall 245/50R18 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 15 tires in this size. Their published revolutions per mile work out to 26.9″ under load (below).

Real 245/50R18 tires measure 27.60–28.10″, against 27.65″ from the size code. Most run taller than the size code (13 of 15).

  1. Michelin Pilot Sport All-Season 428.10″ +0.45″
  2. Michelin Primacy MXM427.70″ +0.05″
  3. Michelin Primacy Tour A/S27.70″ +0.05″
  4. BFGoodrich Advantage Control27.68″ +0.03″
  5. Michelin Pilot Alpin PA4 · 227.68″ +0.03″
  6. Michelin Primacy 327.68″ +0.03″
  7. Michelin X-Ice Snow27.68″ +0.03″
  8. Michelin X-Ice Snow+27.68″ +0.03″
  9. Toyo Proxes G-Tour27.68″ +0.03″
  10. Toyo Extensa A/S II27.68″ +0.03″
  11. Toyo Observe G3-Ice27.68″ +0.03″
  12. Toyo Proxes Sport A/S27.68″ +0.03″
  13. General AltiMAX RT4527.60″ −0.05″
  14. General G-MAX AS0727.60″ −0.05″
Each bar runs from the size code's 27.65″ (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 load26.9″

Published revs per mile (751) mean the tire rolls like a 26.9″ tire on the vehicle. Use this for speedometer calibration.

Weight spread24.4–33.7 lb

The lightest (General AltiMAX RT45, SL) is 9.3 lb lighter per corner than the heaviest (Michelin Primacy MXM4, SL).

15 tires in 245/50R18

Sort by the spec you care about.

LoadRevs/miSource
General AltiMAX RT45TouringSL · 100V27.6024.411.01,764751Spec page
Michelin Primacy Tour A/STouringXL · 104W27.7027.98.51,984751Spec page
General G-MAX AS07PerformanceSL · 100W27.6028.310.01,764751Spec page
Michelin Pilot Alpin PA4WinterXL · 104V27.6828.310.51,984751Spec page
Michelin Pilot Sport All-Season 4PerformanceXL · 104Y28.1029.110.01,984751Spec page
Michelin X-Ice SnowWinterXL · 104H27.6829.110.51,984751Spec page
Michelin X-Ice Snow+WinterXL · 104H27.6829.410.51,984751Spec page
Toyo Proxes Sport A/SPerformanceSL · 100Y27.6829.79.71,764751Spec page
Toyo Proxes G-TourXL · 104W27.6830.211.21,984751Spec page
Toyo Extensa A/S IIAll-seasonSL · 100V27.6830.210.81,764751Spec page
BFGoodrich Advantage ControlAll-seasonXL · 104V27.6831.210.51,984751Spec page
Toyo Observe G3-IceWinterSL · 100T27.6831.311.31,764751Spec page
Michelin Pilot Alpin PA4WinterSL · 100H27.6833.510.51,764751Spec page
Michelin Primacy 3PerformanceSL · 100W27.6833.59.01,764751Spec page
Michelin Primacy MXM4TouringSL · 100V27.7033.79.51,764751Spec page

Is 245/50R18 a 28-inch tire?

≈28″

Yes. The size code works out to 27.65″, and the 15 tires here publish 27.60–28.10″, so people call it a 28.

All 28-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

SizeDiameter ″vs 245/50R18Difference
285/40R1826.98-0.67″-2.4%
255/45R1827.04-0.61″-2.2%
235/50R1827.25-0.39″-1.4%
215/55R1827.31-0.33″-1.2%
265/45R1827.39-0.26″-0.9%
345/35R1827.51-0.14″-0.5%
225/60R1727.63-0.02″-0.1%
275/40R1927.66+0.02″+0.1%
225/55R1827.74+0.10″+0.4%
235/55R1828.18+0.53″+1.9%

How to read 245/50R18

How to read any tire size

245/50R18 100V as printed on the tire sidewall, with each part numbered245/50R18 100V123456
How 245/50R18 100V is printed on the sidewall. It's the most common code among the 15 tires here (3 of them); tires in this size come in other load and speed ratings too.
1245Section width

245 mm across the widest point, or 9.65 inches. Every 245 size

250Aspect ratio

A percentage, not a measurement: the sidewall is 50% as tall as the tire is wide, which is 122.5 mm or 4.82 inches.

3RConstruction

Radial construction.

418Wheel diameter

Mounts on a 18-inch wheel. Approved wheel widths run 7.0″ to 8.5″.

5100Load index

Each tire carries up to 1,764 lb (800 kg) at its maximum pressure.

6VSpeed rating

Rated for up to 149 mph sustained.

SpecificationInchesMetric
Overall diameter27.65702 mm
Section width9.65245 mm
Sidewall height4.82122.5 mm
Circumference86.92,206 mm
Revolutions per mile (calculated, unloaded)729.5453 per km
Revolutions per mile (published by manufacturers)751466–467 per km
Approved wheel width7.0–8.5178–216 mm

Speedometer error after switching to 245/50R18

Your actual speed– mph

Questions about 245/50R18

What is 245/50R18 in inches?

27.65 inches tall, 9.65 inches wide, on a 18-inch wheel. Written in inches, that is roughly 27.6×9.6R18.

How much does a 245/50R18 tire weigh?

Between 24.4 lb and 33.7 lb for the 15 tires listed here. The lightest is the General AltiMAX RT45 (SL); the heaviest is the Michelin Primacy MXM4 (SL).

What wheel width do I need for 245/50R18?

Manufacturers approve 7.0–8.5″ wide wheels for this size.

How many revolutions per mile does a 245/50R18 make?

Published figures run 751 revolutions per mile. The calculated figure is 729.5, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 245/50R18 than 345/35R18?

0.14 inches taller on paper (27.65″ vs 27.51″), which raises the axle about 0.07″. Your speedometer will read about 0.5% slow.