285/55R20 tire size
285/55R20 is a metric size: 32.3" tall, 11.2" wide, on a 20" rim — about a 32.5x11.00R20. The sidewall is 6.2" and the tire turns 624 times per mile.
285/55R20 specs
| Overall diameter (height) | 32.34" · 822 mm |
|---|---|
| Section width | 11.22" · 285 mm |
| Sidewall height | 6.17" · 157 mm (55% of width) |
| Rim diameter | 20" |
| Circumference | 101.61" · 2.581 m |
| Revolutions per mile | 624 (387 per km) |
| Inch (flotation) equivalent | 32.5x11.00R20 |
Equivalent sizes on a 20" 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 | |
|---|---|---|---|---|---|
| 275/55R20 common | 31.91" | -1.34% | -10 mm | 59.2 mph | compare → |
| 275/60R20 common | 32.99" | +2.01% | -10 mm | 61.2 mph | compare → |
| 255/55R20 common | 31.04" | -4.02% | -30 mm | 57.6 mph | compare → |
| 265/60R20 common | 32.52" | +0.55% | -20 mm | 60.3 mph | compare → |
| 305/55R20 common | 33.21" | +2.68% | +20 mm | 61.6 mph | compare → |
| 285/60R20 common | 33.46" | +3.47% | 0 mm | 62.1 mph | compare → |
| 275/50R20 common | 30.83" | -4.69% | -10 mm | 57.2 mph | compare → |
| 33x12.50R20 common | 33.00" | +2.03% | +33 mm | 61.2 mph | compare → |
| 295/60R20 | 33.94" | +4.93% | +10 mm | 63.0 mph | compare → |
| 295/55R20 | 32.78" | +1.34% | +10 mm | 60.8 mph | compare → |
| 285/50R20 | 31.22" | -3.47% | 0 mm | 57.9 mph | compare → |
| 245/60R20 | 31.57" | -2.37% | -40 mm | 58.6 mph | compare → |
| 305/50R20 | 32.01" | -1.03% | +20 mm | 59.4 mph | compare → |
| 255/60R20 | 32.05" | -0.91% | -30 mm | 59.5 mph | compare → |
| 33x13.50R20 | 33.00" | +2.03% | +58 mm | 61.2 mph | calculate → |
| 235/60R20 | 31.10" | -3.83% | -50 mm | 57.7 mph | calculate → |
| 33x11.50R20 | 33.00" | +2.03% | +7 mm | 61.2 mph | calculate → |
| 325/50R20 | 32.80" | +1.40% | +40 mm | 60.8 mph | calculate → |
| 33x12.00R20 | 33.00" | +2.03% | +20 mm | 61.2 mph | calculate → |
| 33x22.00R20 | 33.00" | +2.03% | +274 mm | 61.2 mph | calculate → |
| 265/55R20 | 31.48" | -2.68% | -20 mm | 58.4 mph | calculate → |
| 375/45R20 | 33.29" | +2.92% | +90 mm | 61.8 mph | calculate → |
| 31x18.00R20 | 31.00" | -4.15% | +172 mm | 57.5 mph | calculate → |
| 305/45R20 | 30.81" | -4.75% | +20 mm | 57.2 mph | calculate → |
| 315/50R20 | 32.40" | +0.18% | +30 mm | 60.1 mph | calculate → |
| 33x14.50R20 | 33.00" | +2.03% | +83 mm | 61.2 mph | calculate → |
| 295/50R20 | 31.61" | -2.25% | +10 mm | 58.6 mph | calculate → |
Plus / minus sizing: 19" and 21" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 255/65R19 | 32.05" | -0.90% | -30 mm | 59.5 mph | calculate → |
| 315/45R21 | 32.16" | -0.56% | +30 mm | 59.7 mph | calculate → |
Try another size against 285/55R20
Questions
What size is 285/55R20 in inches?
285/55R20 is about 32.3" tall and 11.2" wide on a 20-inch rim — roughly a 32.5x11.00R20 in inch sizing.
What does 285/55R20 mean?
285 mm section width, sidewall 55% of the width (6.17"), radial construction, 20-inch rim.
What tire sizes are equivalent to 285/55R20?
On the same 20" rim, within 3% of the diameter: 315/50R20 (+0.18%), 265/60R20 (+0.55%), 255/60R20 (-0.91%), 305/50R20 (-1.03%), 275/55R20 (-1.34%), 295/55R20 (+1.34%).
How many revolutions per mile does a 285/55R20 tire make?
About 624 revolutions per mile (circumference 101.6").
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.