35.8" tall, 12.4" wide, 9.9" sidewall
A 315/80R16 tire is 35.8 inches (910 mm) tall and 12.4 inches wide. The sidewall is 80% of the width, 9.9 inches, on a 16-inch wheel, and the tire turns about 563 times per mile.
In flotation terms that is about 35.8x12.4R16. People often call it a 36-inch tire.
The size most often compared with it is 325/80R16, which is 0.6" taller (+1.8%). At an indicated 60 mph you would be doing 61.1 mph on it.
| Current | New | Difference |
|---|
| Shows | Actual speed |
|---|
Same 16" wheel, within 20 mm of width and 10 points of aspect ratio.
| Size | Diameter | Width | Sidewall | vs 315/80R16 | |
|---|---|---|---|---|---|
| 325/80R16 | 36.5" | 12.8" | 10.2" | +1.8% | |
| 325/75R16 | 35.2" | 12.8" | 9.6" | −1.8% | |
| 315/75R16 | 34.6" | 12.4" | 9.3" | −3.5% | |
| 305/75R16 | 34.0" | 12.0" | 9.0" | −5.1% | |
| 295/75R16 | 33.4" | 11.6" | 8.7" | −6.8% | |
| 315/70R16 | 33.4" | 12.4" | 8.7" | −6.9% | |
| 305/70R16 | 32.8" | 12.0" | 8.4" | −8.5% | |
| 295/70R16 | 32.3" | 11.6" | 8.1" | −10.0% |
Sizes within 2% of 35.8" on 18" or 17" wheels.
| Size | Diameter | Width | Sidewall | vs 315/80R16 | |
|---|---|---|---|---|---|
| 325/70R18 | 35.9" | 12.8" | 9.0" | +0.2% | |
| 285/80R18 | 36.0" | 11.2" | 9.0" | +0.3% | |
| 305/75R18 | 36.0" | 12.0" | 9.0" | +0.5% | |
| 285/85R17 | 36.1" | 11.2" | 9.5" | +0.6% | |
| 315/75R17 | 35.6" | 12.4" | 9.3" | −0.7% | |
| 295/80R17 | 35.6" | 11.6" | 9.3" | −0.7% |
Actual speed when the speedometer is calibrated for 315/80R16.
| Speedometer shows | on 325/80R16 | on 325/75R16 | on 315/75R16 |
|---|---|---|---|
| 30 mph | 30.5 mph | 29.5 mph | 29.0 mph |
| 45 mph | 45.8 mph | 44.2 mph | 43.4 mph |
| 60 mph | 61.1 mph | 58.9 mph | 57.9 mph |
| 70 mph | 71.2 mph | 68.7 mph | 67.6 mph |
35.8 inches (910 mm). The sidewall is 9.9 inches.
12.4 inches (315 mm) section width, measured sidewall to sidewall.
About 35.8x12.4R16.
325/80R16 is +1.8% in diameter, within the common 3% guideline. It is 0.4" wider.