Tire Ruler235/60R18 dimensions
| Overall diameter (height) | 29.10″ · 739 mm |
| Section width | 9.25″ · 235 mm |
| Sidewall height | 5.55″ · 141 mm |
| Wheel diameter | 18″ |
| Rim width (rule of thumb) | 6.5–8″ |
| Circumference | 91.4″ |
| Revolutions per mile | 693 |
| In inches (flotation style) | 29.1 × 9.3R18 |
How it’s calculated: the sidewall is 60% of the 235 mm width = 141.0 mm (5.55″). Add two sidewalls to the 18″ wheel: 18 + 2 × 5.55 = 29.10″.
Bigger tires than 235/60R18 on 18″ wheels
| Size | Height | Taller by | 60 mph reads |
|---|---|---|---|
| 245/60R18 | 29.6″ | +0.47″ (+1.6%) | 61.0 mph |
| 235/65R18 | 30.0″ | +0.93″ (+3.2%) | 61.9 mph |
| 265/60R18 | 30.5″ | +1.42″ (+4.9%) | 62.9 mph |
| 245/65R18 | 30.5″ | +1.44″ (+4.9%) | 63.0 mph |
| 275/60R18 | 31.0″ | +1.89″ (+6.5%) | 63.9 mph |
“60 mph reads” is your real speed when a speedometer set up for 235/60R18 shows 60. Above about 3% taller, most trucks need a leveling kit or lift, and the speedometer should be recalibrated.
Sizes equivalent to 235/60R18
Within 1.5% of the same height on an 18″ wheel. Usually interchangeable for the speedometer; check width, load index and clearance.
| Size | Height | Width | Difference |
|---|---|---|---|
| 255/55R18 | 29.0″ | 10.0″ | −0.2% |
Same height on a different wheel size
Changing wheel size (plus or minus sizing) while keeping the overall height keeps your speedometer right:
- 235/75R15: 28.9″ tall on a 15″ wheel (−0.8%)
- 225/75R16: 29.3″ tall on a 16″ wheel (+0.6%)
- 245/70R16: 29.5″ tall on a 16″ wheel (+1.4%)
- 235/70R16: 29.0″ tall on a 16″ wheel (−0.5%)
- 235/65R17: 29.0″ tall on a 17″ wheel (−0.3%)
- 235/55R19: 29.2″ tall on a 19″ wheel (+0.3%)
- 255/50R19: 29.0″ tall on a 19″ wheel (−0.2%)
- 255/45R20: 29.0″ tall on a 20″ wheel (−0.2%)
- 245/45R20: 28.7″ tall on a 20″ wheel (−1.4%)
- 265/45R20: 29.4″ tall on a 20″ wheel (+1.0%)
Popular 235/60R18 comparisons
Frequently asked questions
Is 235/60R18 a 29 inch tire?
Yes. 235/60R18 is 29.10 inches tall, so it's sold and talked about as a 29-inch tire.
What size is 235/60R18 in inches?
235/60R18 is 29.1 inches tall (overall diameter), 9.3 inches wide, with a 5.6 inch sidewall, and fits an 18 inch wheel.
What tire size is equivalent to 235/60R18?
Sizes within 1.5% of the same diameter on an 18" wheel: 255/55R18 (29.0"). Check load index and width before swapping.
What rim width fits 235/60R18?
As a rule of thumb, about 6.5–8 inches. The tire maker's spec sheet lists the approved range for each model.
How many revolutions per mile does 235/60R18 make?
About 693 revolutions per mile in theory (circumference 91.4 in). Real tires turn slightly more because they flatten under load.