255/60R18 tire size
A 255/60R18 tire is 30.0 inches tall and 10.0 inches wide. Here are its full dimensions, what the numbers mean, and the sizes you can swap it for.
- Overall diameter
- 30.05″ (763 mm)
- Section width
- 10.04″ (255 mm)
- Sidewall height
- 6.02″ (153 mm)
- Wheel diameter
- 18″
- Circumference
- 94.4″
- Revolutions per mile
- 671
What 255/60R18 means
- 255: the tire is 255 mm (10.0 in) wide from sidewall to sidewall.
- 60: the sidewall is 60% of the width, 153.0 mm (6.02 in) tall.
- R: radial construction, used by almost every modern tire.
- 18: it fits a 18-inch wheel.
Overall diameter = 18 + 2 × 6.02 = 30.05 inches.
Sizes equivalent to 255/60R18
These sizes are within 3% of the overall diameter, the usual limit for swapping without speedometer problems.
| Size | Diameter | Difference | Speedometer at 60 mph |
|---|---|---|---|
| 255/55R19 | 30.0″ | -0.0% | 60.0 mph actual |
| 255/50R20 | 30.0″ | -0.0% | 60.0 mph actual |
| 235/65R18 | 30.0″ | -0.1% | 60.0 mph actual |
| 235/60R19 | 30.1″ | +0.2% | 60.1 mph actual |
| 235/55R20 | 30.2″ | +0.4% | 60.3 mph actual |
| 275/55R18 | 29.9″ | -0.5% | 59.7 mph actual |
| 275/50R19 | 29.8″ | -0.7% | 59.6 mph actual |
| 275/45R20 | 29.7″ | -1.0% | 59.4 mph actual |
| 265/50R20 | 30.4″ | +1.3% | 60.8 mph actual |
| 245/50R20 | 29.6″ | -1.3% | 59.2 mph actual |
Going a size taller? 265/60R18 is 30.5″ tall, 1.6% more than 255/60R18. Compare any two sizes in the tire size calculator.
See every common size side by side in the tire size chart.
Questions
What is 255/60R18 in inches?
A 255/60R18 tire is about 30.0 inches tall (763 mm) and 10.0 inches wide, on a 18-inch wheel. In flotation sizing that's roughly 30.0x10.0R18.
How tall is a 255/60R18 tire?
The overall diameter is 30.05 inches: the 18-inch wheel plus two 6.02-inch sidewalls. Actual tires vary by a few tenths of an inch between brands and models.
Can I put 265/60R18 instead of 255/60R18?
265/60R18 is 0.47 inches taller (1.6%) and 10 mm wider. That's within the usual 3% limit, but check that your wheel width is approved for it and that it clears the suspension.
How many revolutions per mile does a 255/60R18 make?
About 671 revolutions per mile, from a circumference of 94.4 inches.
