Tire size in inches and millimeters
255/75R17 tire size in inches
A 255/75R17 tire is 32.06 inches tall (814.3 mm) and 10.04 inches wide (255 mm), with a 7.53-inch sidewall (191.3 mm). In inch notation that is about 32.1x10.0R17, close to a 32-inch tire (nominal).
Its circumference is 100.72 inches (2,558.2 mm), or about 629 revolutions per mile.
Nominal 255/75R17 dimensions
- Overall diameter
- 32.06 in814.3 mm
- Section width
- 10.04 in255 mm
- Sidewall height
- 7.53 in191.3 mm
- Circumference
- 100.72 in2,558.2 mm
- Rim diameter
- 17 in
- Revolutions per mile
- 629nominal, from geometric circumference
- Inch notation
- 32.1x10.0R17approximate
Where 255/75R17 fits
- Inch class: 32.06 in is within 0.1 in of a true 32 inches, so the 32-inch label is close to exact.
- Profile: the 17-inch rim plus two 7.53 in sidewalls make up the overall diameter, and the sidewalls are 47% of it. At 75 series that is a very tall profile: the two sidewalls are close to half of the overall diameter.
- Same 17-inch rim: 255/75R17 is the tallest 17-inch size in the catalog. The next shorter is 235/80R17 (31.80 in, -0.80%).
- Same 255 mm width: the closest in diameter are 255/65R18 (31.05 in, -3.14%), 255/70R17 (31.06 in, -3.13%), 255/75R16 (31.06 in, -3.12%), 255/70R18 (32.06 in, -0.01%). At the same width, a different profile or rim changes sidewall height and overall diameter, not section width.
Reading the marking: 255 is the section width in millimeters, 75 is the sidewall height as a percentage of that width, and R17 means radial construction for a 17-inch rim. Percentages are measured from 255/75R17.
Similar sizes on other rim diameters
Within 3% of 255/75R17's overall diameter, nearest first. The speed column is the actual speed when a speedometer calibrated for 255/75R17 reads 60 mph.
| Size | Overall diameter | Diameter change | At 60 mph indicated | Compare |
|---|---|---|---|---|
| 255/70R18 | 32.06 in | -0.01% | 59.99 mph | No comparison page |
| 275/65R18 | 32.07 in | +0.05% | 60.03 mph | No comparison page |
| 235/85R16 | 31.73 in | -1.03% | 59.38 mph | Comparison page for 255/75R17 vs 235/85R16 |
| 265/75R16 | 31.65 in | -1.28% | 59.23 mph | No comparison page |
| 265/65R18 | 31.56 in | -1.55% | 59.07 mph | No comparison page |
| 275/70R16 | 31.16 in | -2.81% | 58.31 mph | No comparison page |
For a size without a comparison page, open 255/75R17 in the calculator and enter that size as the proposed tire.
Important: These results compare nominal dimensions. They do not confirm vehicle fitment. Actual clearance varies by tire model, approved rim width, wheel construction, suspension, alignment, body tolerances, steering angle, load, and brake geometry. Verify load and speed ratings and physically test-fit the complete setup before driving.
Physical checks before changing size
- Approved rim-width range for the exact tire model
- Load index and speed rating equal to or greater than vehicle requirements
- Brake-caliper, hub, and wheel-fastener compatibility
- Fender, liner, suspension, and full-lock steering clearance
- Clearance at full compression and under expected load
- Alignment, tire pressure, and manufacturer guidance
- Professional inspection when variance or clearance is uncertain
Compare another setup
See diameter, speedometer, ride-height, and wheel-position changes.
The calculator opens with 255/75R17 as the current tire and 235/85R16, the published comparison closest in overall diameter, as the proposed tire. Change either size; wheel details stay unknown until you supply them.
Compare 255/75R17 with 235/85R16 in the calculatorPublished comparisons for 255/75R17
1 of 2 keep the 17-inch rim. Diameter changes are measured from 255/75R17.
Same 17-inch rim
- 255/75R17 vs 265/70R17 -1.41% diameter
Smaller wheels
- 255/75R17 vs 235/85R16 -1.03% diameter
Size source and limits
Listed as a recorded tire size (source: NHTSA consumer-complaint records through May 2021, checked August 19, 2026; see methodology). A recorded size is not a safety, popularity, availability, or fitment rating.
Read the formulas and source policy. Read the editorial and corrections policy.