145/70R18 tire size
145/70R18 is a metric size: 26.0" tall, 5.7" wide, on a 18" rim — about a 26x5.50R18. The sidewall is 4.0" and the tire turns 776 times per mile.
145/70R18 specs
| Overall diameter (height) | 25.99" · 660 mm |
|---|---|
| Section width | 5.71" · 145 mm |
| Sidewall height | 4.00" · 102 mm (70% of width) |
| Rim diameter | 18" |
| Circumference | 81.66" · 2.074 m |
| Revolutions per mile | 776 (482 per km) |
| Inch (flotation) equivalent | 26x5.50R18 |
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" | -0.08% | +80 mm | 60.0 mph | calculate → |
| 245/40R18 common | 25.72" | -1.06% | +100 mm | 59.4 mph | calculate → |
| 225/40R18 common | 25.09" | -3.48% | +80 mm | 57.9 mph | calculate → |
| 245/45R18 common | 26.68" | +2.65% | +100 mm | 61.6 mph | calculate → |
| 235/50R18 common | 27.25" | +4.85% | +90 mm | 62.9 mph | calculate → |
| 235/45R18 common | 26.33" | +1.29% | +90 mm | 60.8 mph | calculate → |
| 235/40R18 common | 25.40" | -2.27% | +90 mm | 58.6 mph | calculate → |
| 225/50R18 common | 26.86" | +3.33% | +80 mm | 62.0 mph | calculate → |
| 255/35R18 common | 25.03" | -3.71% | +110 mm | 57.8 mph | calculate → |
| 255/40R18 common | 26.03" | +0.15% | +110 mm | 60.1 mph | calculate → |
| 275/35R18 common | 25.58" | -1.59% | +130 mm | 59.0 mph | calculate → |
| 265/35R18 common | 25.30" | -2.65% | +120 mm | 58.4 mph | calculate → |
| 255/45R18 common | 27.04" | +4.01% | +110 mm | 62.4 mph | calculate → |
| 275/40R18 common | 26.66" | +2.57% | +130 mm | 61.5 mph | calculate → |
| 215/45R18 common | 25.62" | -1.44% | +70 mm | 59.1 mph | calculate → |
| 245/35R18 common | 24.75" | -4.77% | +100 mm | 57.1 mph | calculate → |
| 215/40R18 | 24.77" | -4.70% | +70 mm | 57.2 mph | calculate → |
| 285/35R18 | 25.85" | -0.53% | +140 mm | 59.7 mph | calculate → |
| 265/40R18 | 26.35" | +1.36% | +120 mm | 60.8 mph | calculate → |
| 295/30R18 | 24.97" | -3.94% | +150 mm | 57.6 mph | calculate → |
| 315/30R18 | 25.44" | -2.12% | +170 mm | 58.7 mph | calculate → |
| 285/30R18 | 24.73" | -4.85% | +140 mm | 57.1 mph | calculate → |
| 295/35R18 | 26.13" | +0.53% | +150 mm | 60.3 mph | calculate → |
| 335/30R18 | 25.91" | -0.30% | +190 mm | 59.8 mph | calculate → |
| 215/50R18 | 26.46" | +1.82% | +70 mm | 61.1 mph | calculate → |
| 295/40R18 | 27.29" | +5.00% | +150 mm | 63.0 mph | calculate → |
| 285/40R18 | 26.98" | +3.79% | +140 mm | 62.3 mph | calculate → |
| 305/35R18 | 26.41" | +1.59% | +160 mm | 61.0 mph | calculate → |
| 26x12.00R18 | 26.00" | +0.03% | +160 mm | 60.0 mph | calculate → |
| 26x6.00R18 | 26.00" | +0.03% | +7 mm | 60.0 mph | calculate → |
| 26x8.00R18 | 26.00" | +0.03% | +58 mm | 60.0 mph | calculate → |
| 155/70R18 | 26.54" | +2.12% | +10 mm | 61.3 mph | calculate → |
| 155/60R18 | 25.32" | -2.57% | +10 mm | 58.5 mph | calculate → |
| 305/30R18 | 25.20" | -3.03% | +160 mm | 58.2 mph | calculate → |
| 325/35R18 | 26.96" | +3.71% | +180 mm | 62.2 mph | calculate → |
| 165/70R18 | 27.09" | +4.24% | +20 mm | 62.5 mph | calculate → |
| 145/80R18 | 27.13" | +4.39% | 0 mm | 62.6 mph | calculate → |
| 345/30R18 | 26.15" | +0.61% | +200 mm | 60.4 mph | calculate → |
| 315/35R18 | 26.68" | +2.65% | +170 mm | 61.6 mph | calculate → |
| 205/45R18 | 25.26" | -2.80% | +60 mm | 58.3 mph | calculate → |
| 195/60R18 | 27.21" | +4.70% | +50 mm | 62.8 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 | |
|---|---|---|---|---|---|
| 225/50R17 common | 25.86" | -0.51% | +80 mm | 59.7 mph | calculate → |
| 255/35R19 common | 26.03" | +0.14% | +110 mm | 60.1 mph | calculate → |
| 245/35R19 common | 25.75" | -0.92% | +100 mm | 59.4 mph | calculate → |
| 225/40R19 common | 26.09" | +0.36% | +80 mm | 60.2 mph | calculate → |
| 235/50R17 common | 26.25" | +1.00% | +90 mm | 60.6 mph | calculate → |
| 285/30R19 | 25.73" | -1.00% | +140 mm | 59.4 mph | calculate → |
| 205/55R17 | 25.88" | -0.44% | +60 mm | 59.7 mph | calculate → |
| 305/30R19 | 26.20" | +0.82% | +160 mm | 60.5 mph | calculate → |
| 295/30R19 | 25.97" | -0.09% | +150 mm | 59.9 mph | calculate → |
| 255/45R17 | 26.04" | +0.17% | +110 mm | 60.1 mph | calculate → |
| 335/35R17 | 26.23" | +0.92% | +190 mm | 60.6 mph | calculate → |
| 285/40R17 | 25.98" | -0.06% | +140 mm | 60.0 mph | calculate → |
| 195/60R17 | 26.21" | +0.85% | +50 mm | 60.5 mph | calculate → |
| 175/65R17 | 25.96" | -0.14% | +30 mm | 59.9 mph | calculate → |
| 145/80R17 | 26.13" | +0.55% | 0 mm | 60.3 mph | calculate → |
| 26x6.00R17 | 26.00" | +0.03% | +7 mm | 60.0 mph | calculate → |
| 185/60R17 | 25.74" | -0.97% | +40 mm | 59.4 mph | calculate → |
| 165/70R17 | 26.09" | +0.39% | +20 mm | 60.2 mph | calculate → |
Try another size against 145/70R18
Questions
What size is 145/70R18 in inches?
145/70R18 is about 26.0" tall and 5.7" wide on a 18-inch rim — roughly a 26x5.50R18 in inch sizing.
What does 145/70R18 mean?
145 mm section width, sidewall 70% of the width (4.00"), radial construction, 18-inch rim.
What tire sizes are equivalent to 145/70R18?
On the same 18" rim, within 3% of the diameter: 26x12.00R18 (+0.03%), 26x6.00R18 (+0.03%), 26x8.00R18 (+0.03%), 225/45R18 (-0.08%), 255/40R18 (+0.15%), 335/30R18 (-0.30%).
How many revolutions per mile does a 145/70R18 tire make?
About 776 revolutions per mile (circumference 81.7").
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.