37.0" tall, 12.5" wide on a 18" wheel
A 37x12.50R18 tire is 37.0 inches tall and 12.5 inches wide and mounts on a 18-inch wheel, which leaves a 9.5-inch sidewall. It turns about 545 times per mile.
The size most often compared with it is 305/75R18, which is 1.0" shorter (−2.7%). At an indicated 60 mph you would be doing 58.4 mph on it.
| Current | New | Difference |
|---|
| Shows | Actual speed |
|---|
Same 18" wheel, within 20 mm of width and 10 points of aspect ratio.
| Size | Diameter | Width | Sidewall | vs 37x12.50R18 | |
|---|---|---|---|---|---|
| 305/75R18 | 36.0" | 12.0" | 9.0" | −2.7% | |
| 325/70R18 | 35.9" | 12.8" | 9.0" | −2.9% | |
| 315/70R18 | 35.4" | 12.4" | 8.7" | −4.4% | |
| 35x12.50R18 | 35.0" | 12.5" | 8.5" | −5.4% | |
| 305/70R18 | 34.8" | 12.0" | 8.4" | −5.9% |
Sizes within 2% of 37.0" on 20" or 17" or 16" wheels.
| Size | Diameter | Width | Sidewall | vs 37x12.50R18 | |
|---|---|---|---|---|---|
| 37x11.50R20 | 37.0" | 11.5" | 8.5" | ±0.0% | |
| 37x12.50R17 | 37.0" | 12.5" | 10.0" | ±0.0% | |
| 37x12.50R20 | 37.0" | 12.5" | 8.5" | ±0.0% | |
| 37x13.50R17 | 37.0" | 13.5" | 10.0" | ±0.0% | |
| 37x13.50R20 | 37.0" | 13.5" | 8.5" | ±0.0% | |
| 325/80R16 | 36.5" | 12.8" | 10.2" | −1.4% |
Actual speed when the speedometer is calibrated for 37x12.50R18.
| Speedometer shows | on 305/75R18 | on 325/70R18 | on 315/70R18 |
|---|---|---|---|
| 30 mph | 29.2 mph | 29.1 mph | 28.7 mph |
| 45 mph | 43.8 mph | 43.7 mph | 43.0 mph |
| 60 mph | 58.4 mph | 58.2 mph | 57.3 mph |
| 70 mph | 68.1 mph | 67.9 mph | 66.9 mph |
37.0 inches (940 mm), with a 9.5-inch sidewall on a 18-inch wheel.
There is no common metric size within half an inch of 37.0".
About 545, or 339 per kilometer.