305/60R18 tire size
305/60R18 is a metric size: 32.4" tall, 12.0" wide, on a 18" rim — about a 32.5x12.00R18. The sidewall is 7.2" and the tire turns 622 times per mile.
305/60R18 specs
| Overall diameter (height) | 32.41" · 823 mm |
|---|---|
| Section width | 12.01" · 305 mm |
| Sidewall height | 7.20" · 183 mm (60% of width) |
| Rim diameter | 18" |
| Circumference | 101.82" · 2.586 m |
| Revolutions per mile | 622 (387 per km) |
| Inch (flotation) equivalent | 32.5x12.00R18 |
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 | |
|---|---|---|---|---|---|
| 275/65R18 common | 32.07" | -1.03% | -30 mm | 59.4 mph | compare → |
| 275/70R18 common | 33.16" | +2.31% | -30 mm | 61.4 mph | compare → |
| 265/65R18 common | 31.56" | -2.61% | -40 mm | 58.4 mph | compare → |
| 265/70R18 common | 32.61" | +0.61% | -40 mm | 60.4 mph | compare → |
| 255/70R18 common | 32.06" | -1.09% | -50 mm | 59.3 mph | compare → |
| 255/65R18 common | 31.05" | -4.19% | -50 mm | 57.5 mph | compare → |
| 285/65R18 common | 32.59" | +0.55% | -20 mm | 60.3 mph | compare → |
| 33x12.50R18 | 33.00" | +1.82% | +13 mm | 61.1 mph | compare → |
| 285/60R18 | 31.46" | -2.92% | -20 mm | 58.3 mph | compare → |
| 305/65R18 | 33.61" | +3.71% | 0 mm | 62.2 mph | compare → |
| 275/60R18 | 30.99" | -4.37% | -30 mm | 57.4 mph | compare → |
| 285/70R18 | 33.71" | +4.01% | -20 mm | 62.4 mph | compare → |
| 325/60R18 | 33.35" | +2.92% | +20 mm | 61.7 mph | compare → |
| 245/75R18 | 32.47" | +0.18% | -60 mm | 60.1 mph | calculate → |
| 295/65R18 | 33.10" | +2.13% | -10 mm | 61.3 mph | calculate → |
| 245/70R18 | 31.50" | -2.79% | -60 mm | 58.3 mph | calculate → |
| 235/80R18 | 32.80" | +1.21% | -70 mm | 60.7 mph | calculate → |
| 33x11.50R18 | 33.00" | +1.82% | -13 mm | 61.1 mph | calculate → |
| 33x13.50R18 | 33.00" | +1.82% | +38 mm | 61.1 mph | calculate → |
| 33x13.00R18 | 33.00" | +1.82% | +25 mm | 61.1 mph | calculate → |
| 235/70R18 | 30.95" | -4.49% | -70 mm | 57.3 mph | calculate → |
| 34x12.50R18 | 34.00" | +4.91% | +13 mm | 62.9 mph | calculate → |
| 33x10.50R18 | 33.00" | +1.82% | -38 mm | 61.1 mph | calculate → |
Plus / minus sizing: 17" and 19" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
Try another size against 305/60R18
Questions
What size is 305/60R18 in inches?
305/60R18 is about 32.4" tall and 12.0" wide on a 18-inch rim — roughly a 32.5x12.00R18 in inch sizing.
What does 305/60R18 mean?
305 mm section width, sidewall 60% of the width (7.20"), radial construction, 18-inch rim.
What tire sizes are equivalent to 305/60R18?
On the same 18" rim, within 3% of the diameter: 245/75R18 (+0.18%), 285/65R18 (+0.55%), 265/70R18 (+0.61%), 275/65R18 (-1.03%), 255/70R18 (-1.09%), 235/80R18 (+1.21%).
How many revolutions per mile does a 305/60R18 tire make?
About 622 revolutions per mile (circumference 101.8").
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.