tireheight.com40×15.50R20 in inches
A 40×15.50R20 tire is 40.0″ tall and 15.5″ wide, and fits a 20″ wheel.
How tall 40×15.50R20 tires really are
Heights published by Toyo for the one tire in this size. Their published revolutions per mile work out to 38.6″ under load (below).
The one tire listed, the Toyo Open Country M/T, measures 39.66″: 0.34″ shorter than the size code's 40.00″.
Published revs per mile (523) mean the tire rolls like a 38.6″ tire on the vehicle. Use this for speedometer calibration.
1 tire in 40×15.50R20
Sort by the spec you care about.
Is a 40×15.50R20 really 40 inches tall?
Shorter. The name says 40″, and the 1 tire here publishes 39.66″.
All 40-inch tire sizes, on every wheel size.
Compare with nearby sizes
Differences in overall diameter, calculated from each size code.
| Size | Diameter ″ | vs 40×15.50R20 | Difference |
|---|---|---|---|
| 38×13.50R20 | 38.00 | -2.00″ | -5.0% |
| 38×15.50R20 | 38.00 | -2.00″ | -5.0% |
| 40×13.50R20 | 40.00 | 0.00″ | 0.0% |
| 40×14.50R20 | 40.00 | 0.00″ | 0.0% |
| 42×13.50R20 | 42.00 | +2.00″ | +5.0% |
How to read 40×15.50R20
40 inches tall, measured on the approved wheel. Flotation sizes give every number in inches.
15.50 inches across the widest point, or 394 mm.
Radial construction.
Mounts on a 20-inch wheel. Approved wheel widths run 11.0″ to 14.0″.
Marks a light truck (LT) tire.
Each tire carries up to 4,190 lb (1,900 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 4,190 lb each, as published.
| Specification | Inches | Metric |
|---|---|---|
| Overall diameter | 40.00 | 1016 mm |
| Section width | 15.50 | 394 mm |
| Sidewall height | 10.00 | 254.0 mm |
| Circumference | 125.7 | 3,192 mm |
| Revolutions per mile (calculated, unloaded) | 504.2 | 313 per km |
| Revolutions per mile (published by manufacturers) | 523 | 325 per km |
| Approved wheel width | 11.0–14.0 | 279–356 mm |
Speedometer error after switching to 40×15.50R20
Questions about 40×15.50R20
What is 40×15.50R20 in inches?
40.00 inches tall, 15.50 inches wide, on a 20-inch wheel. Manufacturers publish 39.66 inches for the 1 tires listed here.
What wheel width do I need for 40×15.50R20?
Manufacturers approve 11.0–14.0″ wide wheels for this size.
How many revolutions per mile does a 40×15.50R20 make?
Published figures run 523 revolutions per mile. The calculated figure is 504.2, but manufacturers measure the tire under load, where it rolls on a smaller radius.
How much taller is 40×15.50R20 than 38×15.50R20?
2.00 inches taller on paper (40.00″ vs 38.00″), which raises the axle about 1.00″. Your speedometer will read about 5.3% slow.