245/75R18 tire size
245/75R18 is a metric size: 32.5" tall, 9.6" wide, on a 18" rim — about a 32.5x9.50R18. The sidewall is 7.2" and the tire turns 621 times per mile.
245/75R18 specs
| Overall diameter (height) | 32.47" · 825 mm |
|---|---|
| Section width | 9.65" · 245 mm |
| Sidewall height | 7.23" · 184 mm (75% of width) |
| Rim diameter | 18" |
| Circumference | 102.00" · 2.591 m |
| Revolutions per mile | 621 (386 per km) |
| Inch (flotation) equivalent | 32.5x9.50R18 |
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 | |
|---|---|---|---|---|---|
| 275/65R18 common | 32.07" | -1.21% | +30 mm | 59.3 mph | calculate → |
| 275/70R18 common | 33.16" | +2.12% | +30 mm | 61.3 mph | calculate → |
| 265/65R18 common | 31.56" | -2.79% | +20 mm | 58.3 mph | calculate → |
| 265/70R18 common | 32.61" | +0.42% | +20 mm | 60.3 mph | calculate → |
| 255/70R18 common | 32.06" | -1.27% | +10 mm | 59.2 mph | calculate → |
| 255/65R18 common | 31.05" | -4.37% | +10 mm | 57.4 mph | calculate → |
| 285/65R18 common | 32.59" | +0.36% | +40 mm | 60.2 mph | calculate → |
| 33x12.50R18 | 33.00" | +1.64% | +73 mm | 61.0 mph | calculate → |
| 285/60R18 | 31.46" | -3.09% | +40 mm | 58.1 mph | calculate → |
| 305/65R18 | 33.61" | +3.52% | +60 mm | 62.1 mph | calculate → |
| 275/60R18 | 30.99" | -4.55% | +30 mm | 57.3 mph | calculate → |
| 305/60R18 | 32.41" | -0.18% | +60 mm | 59.9 mph | calculate → |
| 285/70R18 | 33.71" | +3.82% | +40 mm | 62.3 mph | calculate → |
| 325/60R18 | 33.35" | +2.73% | +80 mm | 61.6 mph | calculate → |
| 295/65R18 | 33.10" | +1.94% | +50 mm | 61.2 mph | calculate → |
| 245/70R18 | 31.50" | -2.97% | 0 mm | 58.2 mph | calculate → |
| 235/80R18 | 32.80" | +1.03% | -10 mm | 60.6 mph | calculate → |
| 33x11.50R18 | 33.00" | +1.64% | +47 mm | 61.0 mph | calculate → |
| 33x13.50R18 | 33.00" | +1.64% | +98 mm | 61.0 mph | calculate → |
| 33x13.00R18 | 33.00" | +1.64% | +85 mm | 61.0 mph | calculate → |
| 235/70R18 | 30.95" | -4.67% | -10 mm | 57.2 mph | calculate → |
| 34x12.50R18 | 34.00" | +4.72% | +73 mm | 62.8 mph | calculate → |
| 33x10.50R18 | 33.00" | +1.64% | +22 mm | 61.0 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 | |
|---|---|---|---|---|---|
| 285/70R17 common | 32.71" | +0.74% | +40 mm | 60.4 mph | calculate → |
| 275/70R17 | 32.16" | -0.96% | +30 mm | 59.4 mph | calculate → |
| 305/65R17 | 32.61" | +0.44% | +60 mm | 60.3 mph | calculate → |
| 235/85R17 | 32.73" | +0.80% | -10 mm | 60.5 mph | calculate → |
Try another size against 245/75R18
Questions
What size is 245/75R18 in inches?
245/75R18 is about 32.5" tall and 9.6" wide on a 18-inch rim — roughly a 32.5x9.50R18 in inch sizing.
What does 245/75R18 mean?
245 mm section width, sidewall 75% of the width (7.23"), radial construction, 18-inch rim.
What tire sizes are equivalent to 245/75R18?
On the same 18" rim, within 3% of the diameter: 305/60R18 (-0.18%), 285/65R18 (+0.36%), 265/70R18 (+0.42%), 235/80R18 (+1.03%), 275/65R18 (-1.21%), 255/70R18 (-1.27%).
How many revolutions per mile does a 245/75R18 tire make?
About 621 revolutions per mile (circumference 102.0").
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.