Tire Ruler275/60R18 dimensions
| Overall diameter (height) | 30.99″ · 787 mm |
| Section width | 10.83″ · 275 mm |
| Sidewall height | 6.50″ · 165 mm |
| Wheel diameter | 18″ |
| Rim width (rule of thumb) | 7.5–9.5″ |
| Circumference | 97.4″ |
| Revolutions per mile | 651 |
| In inches (flotation style) | 31.0 × 10.8R18 |
How it’s calculated: the sidewall is 60% of the 275 mm width = 165.0 mm (6.50″). Add two sidewalls to the 18″ wheel: 18 + 2 × 6.50 = 30.99″.
Bigger tires than 275/60R18 on 18″ wheels
| Size | Height | Taller by | 60 mph reads |
|---|---|---|---|
| 265/65R18 | 31.6″ | +0.57″ (+1.8%) | 61.1 mph |
| 255/70R18 | 32.1″ | +1.06″ (+3.4%) | 62.1 mph |
| 275/65R18 | 32.1″ | +1.08″ (+3.5%) | 62.1 mph |
| 285/65R18 | 32.6″ | +1.59″ (+5.1%) | 63.1 mph |
| 265/70R18 | 32.6″ | +1.61″ (+5.2%) | 63.1 mph |
“60 mph reads” is your real speed when a speedometer set up for 275/60R18 shows 60. Above about 3% taller, most trucks need a leveling kit or lift, and the speedometer should be recalibrated.
Sizes equivalent to 275/60R18
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 |
|---|---|---|---|
| 255/65R18 | 31.1″ | 10.0″ | +0.2% |
| 245/65R18 | 30.5″ | 9.6″ | −1.5% |
Same height on a different wheel size
Changing wheel size (plus or minus sizing) while keeping the overall height keeps your speedometer right:
- 31x10.50R15: 31.0″ tall on a 15″ wheel (+0.0%)
- 265/70R16: 30.6″ tall on a 16″ wheel (−1.2%)
- 255/70R17: 31.1″ tall on a 17″ wheel (+0.2%)
- 265/65R17: 30.6″ tall on a 17″ wheel (−1.4%)
- 275/65R17: 31.1″ tall on a 17″ wheel (+0.3%)
- 255/60R19: 31.0″ tall on a 19″ wheel (+0.2%)
- 255/55R20: 31.0″ tall on a 20″ wheel (+0.2%)
- 285/50R20: 31.2″ tall on a 20″ wheel (+0.7%)
- 275/50R20: 30.8″ tall on a 20″ wheel (−0.5%)
- 275/45R21: 30.7″ tall on a 21″ wheel (−0.8%)
- 285/40R22: 31.0″ tall on a 22″ wheel (−0.1%)
Popular 275/60R18 comparisons
Frequently asked questions
Is 275/60R18 a 31 inch tire?
Yes. 275/60R18 is 30.99 inches tall, so it's sold and talked about as a 31-inch tire.
What size is 275/60R18 in inches?
275/60R18 is 31.0 inches tall (overall diameter), 10.8 inches wide, with a 6.5 inch sidewall, and fits an 18 inch wheel.
What tire size is equivalent to 275/60R18?
Sizes within 1.5% of the same diameter on an 18" wheel: 255/65R18 (31.1"), 245/65R18 (30.5"). Check load index and width before swapping.
What rim width fits 275/60R18?
As a rule of thumb, about 7.5–9.5 inches. The tire maker's spec sheet lists the approved range for each model.
How many revolutions per mile does 275/60R18 make?
About 651 revolutions per mile in theory (circumference 97.4 in). Real tires turn slightly more because they flatten under load.