tireheight.com38×13.50R18 in inches
A 38×13.50R18 tire is 38.0″ tall and 13.5″ wide, and fits a 18″ wheel.
How tall 38×13.50R18 tires really are
Heights published by Toyo for all 2 tires in this size. Their published revolutions per mile work out to 36.6–36.7″ under load (below).
Real 38×13.50R18 tires measure 37.66–37.80″, against 38.00″ from the size code. Every one runs shorter than the size code.
- Toyo Open Country R/T Pro37.80″ −0.20″
- Toyo Open Country M/T37.66″ −0.34″
Published revs per mile (550) mean the tire rolls like a 36.6–36.7″ tire on the vehicle. Use this for speedometer calibration.
The lightest (Toyo Open Country R/T Pro, LT E) is 3.1 lb lighter per corner than the heaviest (Toyo Open Country M/T, LT D).
2 tires in 38×13.50R18
Sort by the spec you care about.
Is a 38×13.50R18 really 38 inches tall?
Shorter. The name says 38″, and the 2 tires here publish 37.66–37.80″.
All 38-inch tire sizes, on every wheel size.
Compare with nearby sizes
Differences in overall diameter, calculated from each size code.
| Size | Diameter ″ | vs 38×13.50R18 | Difference |
|---|---|---|---|
| 37×12.50R18 | 37.00 | -1.00″ | -2.6% |
| 37×13.50R18 | 37.00 | -1.00″ | -2.6% |
| 37×12.50R17 | 37.00 | -1.00″ | -2.6% |
| 37×13.50R17 | 37.00 | -1.00″ | -2.6% |
| 38×11.50R18 | 38.00 | 0.00″ | 0.0% |
| 38×15.50R18 | 38.00 | 0.00″ | 0.0% |
| 38×11.50R17 | 38.00 | 0.00″ | 0.0% |
| 38×12.50R17 | 38.00 | 0.00″ | 0.0% |
| 39×13.50R17 | 39.00 | +1.00″ | +2.6% |
| 40×13.50R18 | 40.00 | +2.00″ | +5.3% |
How to read 38×13.50R18
38 inches tall, measured on the approved wheel. Flotation sizes give every number in inches.
13.50 inches across the widest point, or 343 mm.
Radial construction.
Mounts on a 18-inch wheel. Approved wheel widths run 8.5″ to 11.5″.
Marks a light truck (LT) tire.
Each tire carries up to 3,750 lb (1,700 kg) at its maximum pressure.
Rated for up to 99 mph sustained.
Printed separately as "LOAD RANGE D": a 8-ply rating, inflated up to 65 psi (standard load-range table). The load range D tires here carry up to 3,750 lb each, as published.
| Specification | Inches | Metric |
|---|---|---|
| Overall diameter | 38.00 | 965 mm |
| Section width | 13.50 | 343 mm |
| Sidewall height | 10.00 | 254.0 mm |
| Circumference | 119.4 | 3,032 mm |
| Revolutions per mile (calculated, unloaded) | 530.7 | 330 per km |
| Revolutions per mile (published by manufacturers) | 550 | 342 per km |
| Approved wheel width | 8.5–11.5 | 216–292 mm |
Speedometer error after switching to 38×13.50R18
Questions about 38×13.50R18
What is 38×13.50R18 in inches?
38.00 inches tall, 13.50 inches wide, on a 18-inch wheel. Manufacturers publish 37.66–37.80 inches for the 2 tires listed here.
How much does a 38×13.50R18 tire weigh?
Between 89.1 lb and 92.2 lb for the 2 tires listed here. The lightest is the Toyo Open Country R/T Pro (LT E); the heaviest is the Toyo Open Country M/T (LT D).
What wheel width do I need for 38×13.50R18?
Manufacturers approve 8.5–11.5″ wide wheels for this size.
How many revolutions per mile does a 38×13.50R18 make?
Published figures run 550 revolutions per mile. The calculated figure is 530.7, but manufacturers measure the tire under load, where it rolls on a smaller radius.
How much taller is 38×13.50R18 than 37×13.50R18?
1.00 inches taller on paper (38.00″ vs 37.00″), which raises the axle about 0.50″. Your speedometer will read about 2.7% slow.