285/40R23 tire size
285/40R23 is a metric size: 32.0" tall, 11.2" wide, on a 23" rim — about a 32x11.00R23. The sidewall is 4.5" and the tire turns 631 times per mile.
285/40R23 specs
| Overall diameter (height) | 31.98" · 812 mm |
|---|---|
| Section width | 11.22" · 285 mm |
| Sidewall height | 4.49" · 114 mm (40% of width) |
| Rim diameter | 23" |
| Circumference | 100.46" · 2.552 m |
| Revolutions per mile | 631 (392 per km) |
| Inch (flotation) equivalent | 32x11.00R23 |
Equivalent sizes on a 23" rim
Sizes within ±5% of the overall diameter. Green rows are inside the usual ±3% limit for keeping the speedometer, ABS and gearing right; red rows are bigger changes that need clearance checks.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 295/35R23 | 31.13" | -2.65% | +10 mm | 58.4 mph | calculate → |
| 325/35R23 | 31.96" | -0.06% | +40 mm | 60.0 mph | calculate → |
| 305/40R23 | 32.61" | +1.97% | +20 mm | 61.2 mph | calculate → |
| 275/40R23 | 31.66" | -0.98% | -10 mm | 59.4 mph | calculate → |
| 305/35R23 | 31.41" | -1.79% | +20 mm | 58.9 mph | calculate → |
| 255/40R23 | 31.03" | -2.95% | -30 mm | 58.2 mph | calculate → |
Try another size against 285/40R23
Questions
What size is 285/40R23 in inches?
285/40R23 is about 32.0" tall and 11.2" wide on a 23-inch rim — roughly a 32x11.00R23 in inch sizing.
What does 285/40R23 mean?
285 mm section width, sidewall 40% of the width (4.49"), radial construction, 23-inch rim.
What tire sizes are equivalent to 285/40R23?
On the same 23" rim, within 3% of the diameter: 325/35R23 (-0.06%), 275/40R23 (-0.98%), 305/35R23 (-1.79%), 305/40R23 (+1.97%), 295/35R23 (-2.65%), 255/40R23 (-2.95%).
How many revolutions per mile does a 285/40R23 tire make?
About 631 revolutions per mile (circumference 100.5").
How these numbers are computed
Diameter = rim + 2 × sidewall, sidewall = width × aspect ÷ 100, circumference = π × diameter, revolutions per mile = 63,360 ÷ circumference. Real tires differ by brand by a few tenths of an inch. Last reviewed October 14, 2026.