Tire size in inches and millimeters

245/45R17 tire size in inches

A 245/45R17 tire is 25.68 inches tall (652.3 mm) and 9.65 inches wide (245 mm), with a 4.34-inch sidewall (110.3 mm). In inch notation that is about 25.7x9.7R17, close to a 26-inch tire (nominal).

Its circumference is 80.68 inches (2,049.3 mm), or about 785 revolutions per mile.

Nominal 245/45R17 dimensions

Overall diameter
25.68 in652.3 mm
Section width
9.65 in245 mm
Sidewall height
4.34 in110.3 mm
Circumference
80.68 in2,049.3 mm
Rim diameter
17 in
Revolutions per mile
785nominal, from geometric circumference
Inch notation
25.7x9.7R17approximate

Where 245/45R17 fits

  • Inch class: 25.68 in is 0.32 in short of a true 26 inches, inside the 26-inch class (25.50 to 26.49 in).
  • Profile: the 17-inch rim plus two 4.34 in sidewalls make up the overall diameter, and the sidewalls are 34% 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 225/50R17 (25.86 in, +0.69%) and the next shorter is 215/50R17 (25.46 in, -0.84%).
  • Same 245 mm width: the closest in diameter are 245/40R18 (25.72 in, +0.14%), 245/45R18 (26.68 in, +3.89%), 245/40R19 (26.72 in, +4.03%), 245/45R20 (28.68 in, +11.68%). At the same width, a different profile or rim changes sidewall height and overall diameter, not section width.

Reading the marking: 245 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 245/45R17.

Similar sizes on other rim diameters

Within 3% of 245/45R17's overall diameter, nearest first. The speed column is the actual speed when a speedometer calibrated for 245/45R17 reads 60 mph.

Catalog tire sizes on other rim diameters with an overall diameter close to 245/45R17
SizeOverall diameterDiameter changeAt 60 mph indicatedCompare
205/60R1625.69 in+0.02%60.01 mphComparison page for 245/45R17 vs 205/60R16
245/40R1825.72 in+0.14%60.08 mphNo comparison page
225/55R1625.74 in+0.25%60.15 mphNo comparison page
205/65R1525.49 in-0.74%59.56 mphNo comparison page
225/45R1825.97 in+1.13%60.68 mphNo comparison page
215/65R1526.00 in+1.26%60.75 mphNo comparison page

For a size without a comparison page, open 245/45R17 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 245/45R17 as the current tire and 205/60R16, the published comparison closest in overall diameter, as the proposed tire. Change either size; wheel details stay unknown until you supply them.

Compare 245/45R17 with 205/60R16 in the calculator

Compare 245/45R17 with any size

1 of 2 keep the 17-inch rim. Diameter changes are measured from 245/45R17.

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.