Tire size in inches and millimeters

235/45R17 tire size in inches

A 235/45R17 tire is 25.33 inches tall (643.3 mm) and 9.25 inches wide (235 mm), with a 4.16-inch sidewall (105.8 mm). In inch notation that is about 25.3x9.3R17, close to a 25-inch tire (nominal).

Its circumference is 79.57 inches (2,021.0 mm), or about 796 revolutions per mile.

Nominal 235/45R17 dimensions

Overall diameter
25.33 in643.3 mm
Section width
9.25 in235 mm
Sidewall height
4.16 in105.8 mm
Circumference
79.57 in2,021.0 mm
Rim diameter
17 in
Revolutions per mile
796nominal, from geometric circumference
Inch notation
25.3x9.3R17approximate

Where 235/45R17 fits

  • Inch class: 25.33 in is 0.33 in more than a true 25 inches, inside the 25-inch class (24.50 to 25.49 in).
  • Profile: the 17-inch rim plus two 4.16 in sidewalls make up the overall diameter, and the sidewalls are 33% of it. At 45 series that is a low profile: less sidewall between the rim and the road, so the ride is usually firmer and the wheel is more exposed to potholes and curbs.
  • Same 17-inch rim: the next taller catalog size is 215/50R17 (25.46 in, +0.54%) and the next shorter is 205/50R17 (25.07 in, -1.01%).
  • Same 235 mm width: the closest in diameter are 235/60R16 (27.10 in, +7.01%), 235/55R17 (27.18 in, +7.31%), 235/50R18 (27.25 in, +7.60%), 235/70R15 (27.95 in, +10.37%). At the same width, a different profile or rim changes sidewall height and overall diameter, not section width.

Reading the marking: 235 is the section width in millimeters, 45 is the sidewall height as a percentage of that width, and R17 means radial construction for a 17-inch rim. Percentages are measured from 235/45R17.

Similar sizes on other rim diameters

Within 3% of 235/45R17's overall diameter, nearest first. The speed column is the actual speed when a speedometer calibrated for 235/45R17 reads 60 mph.

Catalog tire sizes on other rim diameters with an overall diameter close to 235/45R17
SizeOverall diameterDiameter changeAt 60 mph indicatedCompare
215/55R1625.31 in-0.06%59.96 mphNo comparison page
205/65R1525.49 in+0.65%60.39 mphComparison page for 235/45R17 vs 205/65R15
215/60R1525.16 in-0.67%59.60 mphNo comparison page
225/40R1825.09 in-0.95%59.43 mphNo comparison page
195/65R1524.98 in-1.37%59.18 mphNo comparison page
205/60R1625.69 in+1.41%60.85 mphNo comparison page

For a size without a comparison page, open 235/45R17 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 235/45R17 as the current tire and 205/65R15, the published comparison closest in overall diameter, as the proposed tire. Change either size; wheel details stay unknown until you supply them.

Compare 235/45R17 with 205/65R15 in the calculator

Compare 235/45R17 with any size

1 of 2 keep the 17-inch rim. Diameter changes are measured from 235/45R17.

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.