155/70R18 tire size
155/70R18 is a metric size: 26.5" tall, 6.1" wide, on a 18" rim — about a 26.5x6.00R18. The sidewall is 4.3" and the tire turns 760 times per mile.
155/70R18 specs
| Overall diameter (height) | 26.54" · 674 mm |
|---|---|
| Section width | 6.10" · 155 mm |
| Sidewall height | 4.27" · 109 mm (70% of width) |
| Rim diameter | 18" |
| Circumference | 83.39" · 2.118 m |
| Revolutions per mile | 760 (472 per km) |
| Inch (flotation) equivalent | 26.5x6.00R18 |
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" | -2.15% | +70 mm | 58.7 mph | calculate → |
| 245/40R18 common | 25.72" | -3.11% | +90 mm | 58.1 mph | calculate → |
| 245/45R18 common | 26.68" | +0.52% | +90 mm | 60.3 mph | calculate → |
| 235/50R18 common | 27.25" | +2.67% | +80 mm | 61.6 mph | calculate → |
| 235/45R18 common | 26.33" | -0.82% | +80 mm | 59.5 mph | calculate → |
| 235/40R18 common | 25.40" | -4.30% | +80 mm | 57.4 mph | calculate → |
| 225/50R18 common | 26.86" | +1.19% | +70 mm | 60.7 mph | calculate → |
| 225/55R18 common | 27.74" | +4.52% | +70 mm | 62.7 mph | calculate → |
| 255/40R18 common | 26.03" | -1.93% | +100 mm | 58.8 mph | calculate → |
| 245/50R18 common | 27.65" | +4.15% | +90 mm | 62.5 mph | calculate → |
| 275/35R18 common | 25.58" | -3.63% | +120 mm | 57.8 mph | calculate → |
| 265/35R18 common | 25.30" | -4.67% | +110 mm | 57.2 mph | calculate → |
| 255/45R18 common | 27.04" | +1.85% | +100 mm | 61.1 mph | calculate → |
| 215/55R18 common | 27.31" | +2.89% | +60 mm | 61.7 mph | calculate → |
| 275/40R18 common | 26.66" | +0.44% | +120 mm | 60.3 mph | calculate → |
| 215/45R18 common | 25.62" | -3.49% | +60 mm | 57.9 mph | calculate → |
| 265/40R18 | 26.35" | -0.74% | +110 mm | 59.6 mph | calculate → |
| 285/35R18 | 25.85" | -2.60% | +130 mm | 58.4 mph | calculate → |
| 315/30R18 | 25.44" | -4.15% | +160 mm | 57.5 mph | calculate → |
| 295/35R18 | 26.13" | -1.56% | +140 mm | 59.1 mph | calculate → |
| 335/30R18 | 25.91" | -2.37% | +180 mm | 58.6 mph | calculate → |
| 275/45R18 | 27.74" | +4.52% | +120 mm | 62.7 mph | calculate → |
| 215/50R18 | 26.46" | -0.30% | +60 mm | 59.8 mph | calculate → |
| 295/40R18 | 27.29" | +2.82% | +140 mm | 61.7 mph | calculate → |
| 265/45R18 | 27.39" | +3.19% | +110 mm | 61.9 mph | calculate → |
| 285/40R18 | 26.98" | +1.63% | +130 mm | 61.0 mph | calculate → |
| 305/35R18 | 26.41" | -0.52% | +150 mm | 59.7 mph | calculate → |
| 345/35R18 | 27.51" | +3.63% | +190 mm | 62.2 mph | calculate → |
| 305/40R18 | 27.61" | +4.00% | +150 mm | 62.4 mph | calculate → |
| 325/35R18 | 26.96" | +1.56% | +170 mm | 60.9 mph | calculate → |
| 26x12.00R18 | 26.00" | -2.05% | +150 mm | 58.8 mph | calculate → |
| 26x6.00R18 | 26.00" | -2.05% | -3 mm | 58.8 mph | calculate → |
| 26x8.00R18 | 26.00" | -2.05% | +48 mm | 58.8 mph | calculate → |
| 145/70R18 | 25.99" | -2.08% | -10 mm | 58.8 mph | calculate → |
| 165/70R18 | 27.09" | +2.08% | +10 mm | 61.2 mph | calculate → |
| 145/80R18 | 27.13" | +2.22% | -10 mm | 61.3 mph | calculate → |
| 145/85R18 | 27.70" | +4.38% | -10 mm | 62.6 mph | calculate → |
| 155/60R18 | 25.32" | -4.60% | 0 mm | 57.2 mph | calculate → |
| 315/35R18 | 26.68" | +0.52% | +160 mm | 60.3 mph | calculate → |
| 345/30R18 | 26.15" | -1.48% | +190 mm | 59.1 mph | calculate → |
| 195/60R18 | 27.21" | +2.52% | +40 mm | 61.5 mph | calculate → |
| 205/60R18 | 27.69" | +4.30% | +50 mm | 62.6 mph | calculate → |
| 205/45R18 | 25.26" | -4.82% | +50 mm | 57.1 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 | |
|---|---|---|---|---|---|
| 225/55R17 common | 26.74" | +0.76% | +70 mm | 60.5 mph | calculate → |
| 245/40R19 common | 26.72" | +0.65% | +90 mm | 60.4 mph | calculate → |
| 215/55R17 common | 26.31" | -0.88% | +60 mm | 59.5 mph | calculate → |
| 235/40R19 common | 26.40" | -0.53% | +80 mm | 59.7 mph | calculate → |
| 275/35R19 common | 26.58" | +0.13% | +120 mm | 60.1 mph | calculate → |
| 265/35R19 common | 26.30" | -0.90% | +110 mm | 59.5 mph | calculate → |
| 325/30R19 | 26.68" | +0.50% | +170 mm | 60.3 mph | calculate → |
| 245/50R17 | 26.65" | +0.39% | +90 mm | 60.2 mph | calculate → |
| 315/30R19 | 26.44" | -0.39% | +160 mm | 59.8 mph | calculate → |
| 195/50R19 | 26.68" | +0.50% | +40 mm | 60.3 mph | calculate → |
| 155/80R17 | 26.76" | +0.83% | 0 mm | 60.5 mph | calculate → |
| 205/60R17 | 26.69" | +0.53% | +50 mm | 60.3 mph | calculate → |
| 295/40R17 | 26.29" | -0.95% | +140 mm | 59.4 mph | calculate → |
Try another size against 155/70R18
Questions
What size is 155/70R18 in inches?
155/70R18 is about 26.5" tall and 6.1" wide on a 18-inch rim — roughly a 26.5x6.00R18 in inch sizing.
What does 155/70R18 mean?
155 mm section width, sidewall 70% of the width (4.27"), radial construction, 18-inch rim.
What tire sizes are equivalent to 155/70R18?
On the same 18" rim, within 3% of the diameter: 215/50R18 (-0.30%), 275/40R18 (+0.44%), 245/45R18 (+0.52%), 305/35R18 (-0.52%), 315/35R18 (+0.52%), 265/40R18 (-0.74%).
How many revolutions per mile does a 155/70R18 tire make?
About 760 revolutions per mile (circumference 83.4").
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.