245/65R18 tire size
245/65R18 is a metric size: 30.5" tall, 9.6" wide, on a 18" rim — about a 30.5x9.50R18. The sidewall is 6.3" and the tire turns 660 times per mile.
245/65R18 specs
| Overall diameter (height) | 30.54" · 776 mm |
|---|---|
| Section width | 9.65" · 245 mm |
| Sidewall height | 6.27" · 159 mm (65% of width) |
| Rim diameter | 18" |
| Circumference | 95.94" · 2.437 m |
| Revolutions per mile | 660 (410 per km) |
| Inch (flotation) equivalent | 30.5x9.50R18 |
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 | |
|---|---|---|---|---|---|
| 235/60R18 common | 29.10" | -4.71% | -10 mm | 57.2 mph | calculate → |
| 265/60R18 common | 30.52" | -0.06% | +20 mm | 60.0 mph | calculate → |
| 245/60R18 common | 29.57" | -3.16% | 0 mm | 58.1 mph | calculate → |
| 255/55R18 common | 29.04" | -4.90% | +10 mm | 57.1 mph | calculate → |
| 265/65R18 common | 31.56" | +3.35% | +20 mm | 62.0 mph | calculate → |
| 235/65R18 common | 30.03" | -1.68% | -10 mm | 59.0 mph | calculate → |
| 255/70R18 common | 32.06" | +4.96% | +10 mm | 63.0 mph | calculate → |
| 255/65R18 common | 31.05" | +1.68% | +10 mm | 61.0 mph | calculate → |
| 255/60R18 | 30.05" | -1.61% | +10 mm | 59.0 mph | calculate → |
| 285/60R18 | 31.46" | +3.03% | +40 mm | 61.8 mph | calculate → |
| 275/60R18 | 30.99" | +1.48% | +30 mm | 60.9 mph | calculate → |
| 165/90R18 | 29.69" | -2.77% | -80 mm | 58.3 mph | calculate → |
| 245/70R18 | 31.50" | +3.16% | 0 mm | 61.9 mph | calculate → |
| 285/50R18 | 29.22" | -4.32% | +40 mm | 57.4 mph | calculate → |
| 175/90R18 | 30.40" | -0.45% | -70 mm | 59.7 mph | calculate → |
| 285/55R18 | 30.34" | -0.64% | +40 mm | 59.6 mph | calculate → |
| 235/70R18 | 30.95" | +1.35% | -10 mm | 60.8 mph | calculate → |
| 275/55R18 | 29.91" | -2.06% | +30 mm | 58.8 mph | calculate → |
| 325/45R18 | 29.52" | -3.35% | +80 mm | 58.0 mph | calculate → |
| 225/65R18 | 29.52" | -3.35% | -20 mm | 58.0 mph | calculate → |
| 265/55R18 | 29.48" | -3.48% | +20 mm | 57.9 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 | |
|---|---|---|---|---|---|
| 245/70R17 common | 30.50" | -0.12% | 0 mm | 59.9 mph | calculate → |
| 265/65R17 common | 30.56" | +0.08% | +20 mm | 60.0 mph | calculate → |
| 265/55R19 | 30.48" | -0.21% | +20 mm | 59.9 mph | calculate → |
| 225/75R17 | 30.29" | -0.83% | -20 mm | 59.5 mph | calculate → |
| 315/55R17 | 30.64" | +0.34% | +70 mm | 60.2 mph | calculate → |
| 165/90R19 | 30.69" | +0.50% | -80 mm | 60.3 mph | calculate → |
| 285/60R17 | 30.46" | -0.24% | +40 mm | 59.9 mph | calculate → |
Try another size against 245/65R18
Questions
What size is 245/65R18 in inches?
245/65R18 is about 30.5" tall and 9.6" wide on a 18-inch rim — roughly a 30.5x9.50R18 in inch sizing.
What does 245/65R18 mean?
245 mm section width, sidewall 65% of the width (6.27"), radial construction, 18-inch rim.
What tire sizes are equivalent to 245/65R18?
On the same 18" rim, within 3% of the diameter: 265/60R18 (-0.06%), 175/90R18 (-0.45%), 285/55R18 (-0.64%), 235/70R18 (+1.35%), 275/60R18 (+1.48%), 255/60R18 (-1.61%).
How many revolutions per mile does a 245/65R18 tire make?
About 660 revolutions per mile (circumference 95.9").
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.