345/30R18 tire size
345/30R18 is a metric size: 26.1" tall, 13.6" wide, on a 18" rim — about a 26x13.50R18. The sidewall is 4.1" and the tire turns 771 times per mile.
345/30R18 specs
| Overall diameter (height) | 26.15" · 664 mm |
|---|---|
| Section width | 13.58" · 345 mm |
| Sidewall height | 4.07" · 103 mm (30% of width) |
| Rim diameter | 18" |
| Circumference | 82.15" · 2.087 m |
| Revolutions per mile | 771 (479 per km) |
| Inch (flotation) equivalent | 26x13.50R18 |
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" | -0.68% | -120 mm | 59.6 mph | calculate → |
| 245/40R18 common | 25.72" | -1.66% | -100 mm | 59.0 mph | calculate → |
| 225/40R18 common | 25.09" | -4.07% | -120 mm | 57.6 mph | calculate → |
| 245/45R18 common | 26.68" | +2.03% | -100 mm | 61.2 mph | calculate → |
| 235/50R18 common | 27.25" | +4.22% | -110 mm | 62.5 mph | calculate → |
| 235/45R18 common | 26.33" | +0.68% | -110 mm | 60.4 mph | calculate → |
| 235/40R18 common | 25.40" | -2.86% | -110 mm | 58.3 mph | calculate → |
| 225/50R18 common | 26.86" | +2.71% | -120 mm | 61.6 mph | calculate → |
| 255/35R18 common | 25.03" | -4.29% | -90 mm | 57.4 mph | calculate → |
| 255/40R18 common | 26.03" | -0.45% | -90 mm | 59.7 mph | calculate → |
| 275/35R18 common | 25.58" | -2.18% | -70 mm | 58.7 mph | calculate → |
| 265/35R18 common | 25.30" | -3.24% | -80 mm | 58.1 mph | calculate → |
| 255/45R18 common | 27.04" | +3.39% | -90 mm | 62.0 mph | calculate → |
| 215/55R18 common | 27.31" | +4.44% | -130 mm | 62.7 mph | calculate → |
| 275/40R18 common | 26.66" | +1.96% | -70 mm | 61.2 mph | calculate → |
| 215/45R18 common | 25.62" | -2.03% | -130 mm | 58.8 mph | calculate → |
| 265/40R18 | 26.35" | +0.75% | -80 mm | 60.5 mph | calculate → |
| 285/35R18 | 25.85" | -1.13% | -60 mm | 59.3 mph | calculate → |
| 295/30R18 | 24.97" | -4.52% | -50 mm | 57.3 mph | calculate → |
| 315/30R18 | 25.44" | -2.71% | -30 mm | 58.4 mph | calculate → |
| 295/35R18 | 26.13" | -0.08% | -50 mm | 60.0 mph | calculate → |
| 335/30R18 | 25.91" | -0.90% | -10 mm | 59.5 mph | calculate → |
| 215/50R18 | 26.46" | +1.20% | -130 mm | 60.7 mph | calculate → |
| 295/40R18 | 27.29" | +4.37% | -50 mm | 62.6 mph | calculate → |
| 265/45R18 | 27.39" | +4.74% | -80 mm | 62.8 mph | calculate → |
| 285/40R18 | 26.98" | +3.16% | -60 mm | 61.9 mph | calculate → |
| 305/35R18 | 26.41" | +0.98% | -40 mm | 60.6 mph | calculate → |
| 26x12.00R18 | 26.00" | -0.57% | -40 mm | 59.7 mph | calculate → |
| 26x6.00R18 | 26.00" | -0.57% | -193 mm | 59.7 mph | calculate → |
| 26x8.00R18 | 26.00" | -0.57% | -142 mm | 59.7 mph | calculate → |
| 145/70R18 | 25.99" | -0.60% | -200 mm | 59.6 mph | calculate → |
| 155/70R18 | 26.54" | +1.51% | -190 mm | 60.9 mph | calculate → |
| 325/35R18 | 26.96" | +3.09% | -20 mm | 61.9 mph | calculate → |
| 155/60R18 | 25.32" | -3.16% | -190 mm | 58.1 mph | calculate → |
| 165/70R18 | 27.09" | +3.61% | -180 mm | 62.2 mph | calculate → |
| 305/30R18 | 25.20" | -3.61% | -40 mm | 57.8 mph | calculate → |
| 145/80R18 | 27.13" | +3.76% | -200 mm | 62.3 mph | calculate → |
| 315/35R18 | 26.68" | +2.03% | -30 mm | 61.2 mph | calculate → |
| 205/45R18 | 25.26" | -3.39% | -140 mm | 58.0 mph | calculate → |
| 195/60R18 | 27.21" | +4.07% | -150 mm | 62.4 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 | |
|---|---|---|---|---|---|
| 215/55R17 common | 26.31" | +0.62% | -130 mm | 60.4 mph | calculate → |
| 235/40R19 common | 26.40" | +0.96% | -110 mm | 60.6 mph | calculate → |
| 255/35R19 common | 26.03" | -0.47% | -90 mm | 59.7 mph | calculate → |
| 225/40R19 common | 26.09" | -0.24% | -120 mm | 59.9 mph | calculate → |
| 235/50R17 common | 26.25" | +0.39% | -110 mm | 60.2 mph | calculate → |
| 265/35R19 common | 26.30" | +0.59% | -80 mm | 60.4 mph | calculate → |
| 305/30R19 | 26.20" | +0.21% | -40 mm | 60.1 mph | calculate → |
| 295/30R19 | 25.97" | -0.69% | -50 mm | 59.6 mph | calculate → |
| 255/45R17 | 26.04" | -0.44% | -90 mm | 59.7 mph | calculate → |
| 335/35R17 | 26.23" | +0.32% | -10 mm | 60.2 mph | calculate → |
| 195/60R17 | 26.21" | +0.24% | -150 mm | 60.1 mph | calculate → |
| 285/40R17 | 25.98" | -0.66% | -60 mm | 59.6 mph | calculate → |
| 145/80R17 | 26.13" | -0.06% | -200 mm | 60.0 mph | calculate → |
| 175/65R17 | 25.96" | -0.74% | -170 mm | 59.6 mph | calculate → |
| 26x6.00R17 | 26.00" | -0.57% | -193 mm | 59.7 mph | calculate → |
| 165/70R17 | 26.09" | -0.21% | -180 mm | 59.9 mph | calculate → |
| 295/40R17 | 26.29" | +0.54% | -50 mm | 60.3 mph | calculate → |
Try another size against 345/30R18
Questions
What size is 345/30R18 in inches?
345/30R18 is about 26.1" tall and 13.6" wide on a 18-inch rim — roughly a 26x13.50R18 in inch sizing.
What does 345/30R18 mean?
345 mm section width, sidewall 30% of the width (4.07"), radial construction, 18-inch rim.
What tire sizes are equivalent to 345/30R18?
On the same 18" rim, within 3% of the diameter: 295/35R18 (-0.08%), 255/40R18 (-0.45%), 26x12.00R18 (-0.57%), 26x6.00R18 (-0.57%), 26x8.00R18 (-0.57%), 145/70R18 (-0.60%).
How many revolutions per mile does a 345/30R18 tire make?
About 771 revolutions per mile (circumference 82.2").
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.