Tire Ruler255/70R17 dimensions
| Overall diameter (height) | 31.06″ · 789 mm |
| Section width | 10.04″ · 255 mm |
| Sidewall height | 7.03″ · 179 mm |
| Wheel diameter | 17″ |
| Rim width (rule of thumb) | 7–9″ |
| Circumference | 97.6″ |
| Revolutions per mile | 649 |
| In inches (flotation style) | 31.1 × 10.0R17 |
How it’s calculated: the sidewall is 70% of the 255 mm width = 178.5 mm (7.03″). Add two sidewalls to the 17″ wheel: 17 + 2 × 7.03 = 31.06″.
Bigger tires than 255/70R17 on 17″ wheels
| Size | Height | Taller by | 60 mph reads |
|---|---|---|---|
| 245/75R17 | 31.5″ | +0.41″ (+1.3%) | 60.8 mph |
| 265/70R17 | 31.6″ | +0.55″ (+1.8%) | 61.1 mph |
| 255/75R17 | 32.1″ | +1.00″ (+3.2%) | 61.9 mph |
| 275/70R17 | 32.2″ | +1.10″ (+3.5%) | 62.1 mph |
| 285/70R17 | 32.7″ | +1.65″ (+5.3%) | 63.2 mph |
“60 mph reads” is your real speed when a speedometer set up for 255/70R17 shows 60. Above about 3% taller, most trucks need a leveling kit or lift, and the speedometer should be recalibrated.
Sizes equivalent to 255/70R17
Within 1.5% of the same height on a 17″ wheel. Usually interchangeable for the speedometer; check width, load index and clearance.
| Size | Height | Width | Difference |
|---|---|---|---|
| 275/65R17 | 31.1″ | 10.8″ | +0.1% |
| 245/75R17 | 31.5″ | 9.6″ | +1.3% |
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 (−0.2%)
- 265/70R16: 30.6″ tall on a 16″ wheel (−1.4%)
- 255/65R18: 31.1″ tall on an 18″ wheel (−0.0%)
- 275/60R18: 31.0″ tall on an 18″ wheel (−0.2%)
- 255/60R19: 31.0″ tall on a 19″ wheel (−0.0%)
- 255/55R20: 31.0″ tall on a 20″ wheel (−0.0%)
- 285/50R20: 31.2″ tall on a 20″ wheel (+0.5%)
- 275/50R20: 30.8″ tall on a 20″ wheel (−0.7%)
- 275/45R21: 30.7″ tall on a 21″ wheel (−1.0%)
- 285/40R22: 31.0″ tall on a 22″ wheel (−0.3%)
Popular 255/70R17 comparisons
Frequently asked questions
Is 255/70R17 a 31 inch tire?
Yes. 255/70R17 is 31.06 inches tall, so it's sold and talked about as a 31-inch tire.
What size is 255/70R17 in inches?
255/70R17 is 31.1 inches tall (overall diameter), 10.0 inches wide, with a 7.0 inch sidewall, and fits a 17 inch wheel.
What tire size is equivalent to 255/70R17?
Sizes within 1.5% of the same diameter on a 17" wheel: 275/65R17 (31.1"), 245/75R17 (31.5"). Check load index and width before swapping.
What rim width fits 255/70R17?
As a rule of thumb, about 7–9 inches. The tire maker's spec sheet lists the approved range for each model.
How many revolutions per mile does 255/70R17 make?
About 649 revolutions per mile in theory (circumference 97.6 in). Real tires turn slightly more because they flatten under load.