215/55R18 tire size
215/55R18 is a metric size: 27.3" tall, 8.5" wide, on a 18" rim — about a 27.5x8.50R18. The sidewall is 4.7" and the tire turns 738 times per mile.
215/55R18 specs
| Overall diameter (height) | 27.31" · 694 mm |
|---|---|
| Section width | 8.46" · 215 mm |
| Sidewall height | 4.66" · 118 mm (55% of width) |
| Rim diameter | 18" |
| Circumference | 85.80" · 2.179 m |
| Revolutions per mile | 738 (459 per km) |
| Inch (flotation) equivalent | 27.5x8.50R18 |
Equivalent sizes on a 18" 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 | |
|---|---|---|---|---|---|
| 225/45R18 common | 25.97" | -4.90% | +10 mm | 57.1 mph | compare → |
| 245/45R18 common | 26.68" | -2.31% | +30 mm | 58.6 mph | compare → |
| 235/50R18 common | 27.25" | -0.22% | +20 mm | 59.9 mph | compare → |
| 235/55R18 common | 28.18" | +3.17% | +20 mm | 61.9 mph | compare → |
| 235/45R18 common | 26.33" | -3.60% | +20 mm | 57.8 mph | compare → |
| 225/60R18 common | 28.63" | +4.83% | +10 mm | 62.9 mph | compare → |
| 225/50R18 common | 26.86" | -1.66% | +10 mm | 59.0 mph | compare → |
| 225/55R18 common | 27.74" | +1.59% | +10 mm | 61.0 mph | compare → |
| 255/40R18 common | 26.03" | -4.69% | +40 mm | 57.2 mph | compare → |
| 245/50R18 common | 27.65" | +1.23% | +30 mm | 60.7 mph | compare → |
| 255/45R18 common | 27.04" | -1.01% | +40 mm | 59.4 mph | compare → |
| 275/40R18 common | 26.66" | -2.38% | +60 mm | 58.6 mph | compare → |
| 245/55R18 | 28.61" | +4.76% | +30 mm | 62.9 mph | compare → |
| 265/40R18 | 26.35" | -3.53% | +50 mm | 57.9 mph | compare → |
| 295/35R18 | 26.13" | -4.32% | +80 mm | 57.4 mph | compare → |
| 275/45R18 | 27.74" | +1.59% | +60 mm | 61.0 mph | compare → |
| 215/50R18 | 26.46" | -3.10% | 0 mm | 58.1 mph | compare → |
| 295/40R18 | 27.29" | -0.07% | +80 mm | 60.0 mph | compare → |
| 265/45R18 | 27.39" | +0.29% | +50 mm | 60.2 mph | compare → |
| 285/40R18 | 26.98" | -1.23% | +70 mm | 59.3 mph | calculate → |
| 345/35R18 | 27.51" | +0.72% | +130 mm | 60.4 mph | calculate → |
| 305/35R18 | 26.41" | -3.32% | +90 mm | 58.0 mph | calculate → |
| 295/45R18 | 28.45" | +4.18% | +80 mm | 62.5 mph | calculate → |
| 255/50R18 | 28.04" | +2.67% | +40 mm | 61.6 mph | calculate → |
| 315/40R18 | 27.92" | +2.23% | +100 mm | 61.3 mph | calculate → |
| 305/40R18 | 27.61" | +1.08% | +90 mm | 60.6 mph | calculate → |
| 215/60R18 | 28.16" | +3.10% | 0 mm | 61.9 mph | calculate → |
| 155/85R18 | 28.37" | +3.89% | -60 mm | 62.3 mph | calculate → |
| 145/80R18 | 27.13" | -0.65% | -70 mm | 59.6 mph | calculate → |
| 165/70R18 | 27.09" | -0.79% | -50 mm | 59.5 mph | calculate → |
| 325/35R18 | 26.96" | -1.30% | +110 mm | 59.2 mph | calculate → |
| 145/85R18 | 27.70" | +1.44% | -70 mm | 60.9 mph | calculate → |
| 28x12.00R18 | 28.00" | +2.52% | +90 mm | 61.5 mph | calculate → |
| 155/70R18 | 26.54" | -2.81% | -60 mm | 58.3 mph | calculate → |
| 285/45R18 | 28.10" | +2.88% | +70 mm | 61.7 mph | calculate → |
| 26x12.00R18 | 26.00" | -4.80% | +90 mm | 57.1 mph | calculate → |
| 26x6.00R18 | 26.00" | -4.80% | -63 mm | 57.1 mph | calculate → |
| 26x8.00R18 | 26.00" | -4.80% | -12 mm | 57.1 mph | calculate → |
| 145/70R18 | 25.99" | -4.83% | -70 mm | 57.1 mph | calculate → |
| 195/60R18 | 27.21" | -0.36% | -20 mm | 59.8 mph | calculate → |
| 205/60R18 | 27.69" | +1.37% | -10 mm | 60.8 mph | calculate → |
| 315/35R18 | 26.68" | -2.31% | +100 mm | 58.6 mph | calculate → |
| 28x10.00R18 | 28.00" | +2.52% | +39 mm | 61.5 mph | calculate → |
| 265/50R18 | 28.43" | +4.11% | +50 mm | 62.5 mph | calculate → |
| 345/30R18 | 26.15" | -4.25% | +130 mm | 57.4 mph | calculate → |
Plus / minus sizing: 17" and 19" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 235/55R17 common | 27.18" | -0.49% | +20 mm | 59.7 mph | compare → |
| 215/60R17 common | 27.16" | -0.56% | 0 mm | 59.7 mph | compare → |
| 235/45R19 common | 27.33" | +0.06% | +20 mm | 60.0 mph | compare → |
| 265/40R19 | 27.35" | +0.13% | +50 mm | 60.1 mph | compare → |
| 295/35R19 | 27.13" | -0.66% | +80 mm | 59.6 mph | compare → |
| 345/30R19 | 27.15" | -0.59% | +130 mm | 59.6 mph | compare → |
| 305/35R19 | 27.41" | +0.35% | +90 mm | 60.2 mph | calculate → |
| 155/70R19 | 27.54" | +0.85% | -60 mm | 60.5 mph | calculate → |
| 355/30R19 | 27.39" | +0.27% | +140 mm | 60.2 mph | calculate → |
| 165/80R17 | 27.39" | +0.30% | -50 mm | 60.2 mph | calculate → |
| 215/50R19 | 27.46" | +0.56% | 0 mm | 60.3 mph | calculate → |
| 255/50R17 | 27.04" | -0.99% | +40 mm | 59.4 mph | calculate → |
| 175/60R19 | 27.27" | -0.16% | -40 mm | 59.9 mph | calculate → |
| 145/90R17 | 27.28" | -0.13% | -70 mm | 59.9 mph | calculate → |
| 205/65R17 | 27.49" | +0.66% | -10 mm | 60.4 mph | calculate → |
Try another size against 215/55R18
Questions
What size is 215/55R18 in inches?
215/55R18 is about 27.3" tall and 8.5" wide on a 18-inch rim — roughly a 27.5x8.50R18 in inch sizing.
What does 215/55R18 mean?
215 mm section width, sidewall 55% of the width (4.66"), radial construction, 18-inch rim.
What tire sizes are equivalent to 215/55R18?
On the same 18" rim, within 3% of the diameter: 295/40R18 (-0.07%), 235/50R18 (-0.22%), 265/45R18 (+0.29%), 195/60R18 (-0.36%), 145/80R18 (-0.65%), 345/35R18 (+0.72%).
How many revolutions per mile does a 215/55R18 tire make?
About 738 revolutions per mile (circumference 85.8").
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.