tireheight.com

37×13.50R18 in inches

A 37×13.50R18 tire is 37.0″ tall and 13.5″ wide, and fits a 18″ wheel.

Diameter37.00″
Width13.50″
Sidewall9.50″
37×13.50R18 drawn to scale: 37.00 inch diameter, 9.50 inch sidewall, 18 inch wheel, 13.50 inch tread width18″ wheel9.50″37.00″ overall13.50″ wideSide view
Drawn to scale. Nominal dimensions calculated from the size code.
Manufacturer data

How tall 37×13.50R18 tires really are

Heights published by BFGoodrich, Mickey Thompson and Toyo for all 5 tires in this size. Their published revolutions per mile work out to 35.4–36.0″ under load (below).

Real 37×13.50R18 tires measure 36.50–37.05″, against 37.00″ from the size code. Most run shorter than the size code (4 of 5).

  1. Toyo Open Country M/T37.05″ +0.05″
  2. Mickey Thompson Baja Legend MTZ36.80″ −0.20″
  3. Toyo Open Country R/T Pro36.80″ −0.20″
  4. BFGoodrich All-Terrain T/A KO336.50″ −0.50″
  5. BFGoodrich Mud-Terrain T/A KM336.50″ −0.50″
Each bar runs from the size code's 37.00″ (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 load35.4–36.0″

Published revs per mile (560–569) mean the tire rolls like a 35.4–36.0″ tire on the vehicle. Use this for speedometer calibration.

Weight spread78.3–90.2 lb

The lightest (BFGoodrich All-Terrain T/A KO3, LT F) is 11.9 lb lighter per corner than the heaviest (Toyo Open Country M/T, LT D).

5 tires in 37×13.50R18

Sort by the spec you care about.

LoadRevs/miSource
BFGoodrich All-Terrain T/A KO3All-terrainLT F · 128R36.5078.316.03,970569Spec page
BFGoodrich Mud-Terrain T/A KM3Mud-terrainLT E · 128Q36.5078.818.03,970569Spec page
Mickey Thompson Baja Legend MTZMud-terrainLT D · 124Q36.8082.022.03,525–Spec page
Toyo Open Country R/T ProRugged-terrainLT E · 128Q36.8085.019.93,970565Spec page
Toyo Open Country M/TMud-terrainLT D · 124Q37.0590.221.03,525560Spec page

Is a 37×13.50R18 really 37 inches tall?

36.7″

Mostly. The name says 37″, and the 5 tires here publish 36.50–37.05″.

All 37-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

SizeDiameter ″vs 37×13.50R18Difference
35×12.50R1835.00-2.00″-5.4%
315/70R1835.36-1.64″-4.4%
37×12.50R1837.000.00″0.0%
37×12.50R1737.000.00″0.0%
37×13.50R1737.000.00″0.0%
38×11.50R1838.00+1.00″+2.7%
38×13.50R1838.00+1.00″+2.7%
38×15.50R1838.00+1.00″+2.7%
38×11.50R1738.00+1.00″+2.7%
38×12.50R1738.00+1.00″+2.7%

How to read 37×13.50R18

How to read any tire size

37X13.50R18LT 128Q as printed on the tire sidewall, with each part numbered37X13.50R18LT 128Q1234567
How 37X13.50R18LT 128Q is printed on the sidewall. It's the most common code among the 5 tires here (2 of them); tires in this size come in other load and speed ratings too.
137Overall diameter

37 inches tall, measured on the approved wheel. Flotation sizes give every number in inches.

213.50Section width

13.50 inches across the widest point, or 343 mm.

3RConstruction

Radial construction.

418Wheel diameter

Mounts on a 18-inch wheel. Approved wheel widths run 8.5″ to 12.0″.

5LTLight truck

Marks a light truck (LT) tire.

6128Load index

Each tire carries up to 3,970 lb (1,800 kg) at its maximum pressure.

7QSpeed rating

Rated for up to 99 mph sustained.

ELoad range

Printed separately as "LOAD RANGE E": a 10-ply rating, inflated up to 80 psi (standard load-range table). The load range E tires here carry up to 3,970 lb each, as published.

SpecificationInchesMetric
Overall diameter37.00940 mm
Section width13.50343 mm
Sidewall height9.50241.3 mm
Circumference116.22,952 mm
Revolutions per mile (calculated, unloaded)545.1339 per km
Revolutions per mile (published by manufacturers)560–569348–354 per km
Approved wheel width8.5–12.0216–305 mm

Speedometer error after switching to 37×13.50R18

Your actual speed– mph

Questions about 37×13.50R18

What is 37×13.50R18 in inches?

37.00 inches tall, 13.50 inches wide, on a 18-inch wheel. Manufacturers publish 36.50–37.05 inches for the 5 tires listed here.

How much does a 37×13.50R18 tire weigh?

Between 78.3 lb and 90.2 lb for the 5 tires listed here. The lightest is the BFGoodrich All-Terrain T/A KO3 (LT F); the heaviest is the Toyo Open Country M/T (LT D).

What wheel width do I need for 37×13.50R18?

Manufacturers approve 8.5–12.0″ wide wheels for this size.

How many revolutions per mile does a 37×13.50R18 make?

Published figures run 560–569 revolutions per mile. The calculated figure is 545.1, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 37×13.50R18 than 315/70R18?

1.64 inches taller on paper (37.00″ vs 35.36″), which raises the axle about 0.82″. Your speedometer will read about 4.6% slow.