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.

Catalog tire sizes on other rim diameters with an overall diameter close to 255/75R17
SizeOverall diameterDiameter changeAt 60 mph indicatedCompare
255/70R1832.06 in-0.01%59.99 mphNo comparison page
275/65R1832.07 in+0.05%60.03 mphNo comparison page
235/85R1631.73 in-1.03%59.38 mphComparison page for 255/75R17 vs 235/85R16
265/75R1631.65 in-1.28%59.23 mphNo comparison page
265/65R1831.56 in-1.55%59.07 mphNo comparison page
275/70R1631.16 in-2.81%58.31 mphNo 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 calculator

Compare 255/75R17 with any size

1 of 2 keep the 17-inch rim. Diameter changes are measured from 255/75R17.

Same 17-inch rim

Smaller wheels

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.