Tire size in inches and millimeters

225/75R15 tire size in inches

A 225/75R15 tire is 28.29 inches tall (718.5 mm) and 8.86 inches wide (225 mm), with a 6.64-inch sidewall (168.8 mm). In inch notation that is about 28.3x8.9R15, close to a 28-inch tire (nominal).

Its circumference is 88.87 inches (2,257.2 mm), or about 713 revolutions per mile.

Nominal 225/75R15 dimensions

Overall diameter
28.29 in718.5 mm
Section width
8.86 in225 mm
Sidewall height
6.64 in168.8 mm
Circumference
88.87 in2,257.2 mm
Rim diameter
15 in
Revolutions per mile
713nominal, from geometric circumference
Inch notation
28.3x8.9R15approximate

Where 225/75R15 fits

  • Inch class: 28.29 in is 0.29 in more than a true 28 inches, inside the 28-inch class (27.50 to 28.49 in).
  • Profile: the 15-inch rim plus two 6.64 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 15-inch rim: the next taller catalog size is 235/75R15 (28.88 in, +2.09%) and the next shorter is 235/70R15 (27.95 in, -1.18%).
  • Same 225 mm width: the closest in diameter are 225/65R16 (27.52 in, -2.73%), 225/60R17 (27.63 in, -2.32%), 225/70R16 (28.40 in, +0.40%), 225/65R17 (28.52 in, +0.81%). At the same width, a different profile or rim changes sidewall height and overall diameter, not section width.

Reading the marking: 225 is the section width in millimeters, 75 is the sidewall height as a percentage of that width, and R15 means radial construction for a 15-inch rim. Percentages are measured from 225/75R15.

Similar sizes on other rim diameters

Within 3% of 225/75R15's overall diameter, nearest first. The speed column is the actual speed when a speedometer calibrated for 225/75R15 reads 60 mph.

Catalog tire sizes on other rim diameters with an overall diameter close to 225/75R15
SizeOverall diameterDiameter changeAt 60 mph indicatedCompare
265/35R2128.30 in+0.06%60.03 mphNo comparison page
265/40R2028.35 in+0.21%60.13 mphNo comparison page
225/70R1628.40 in+0.40%60.24 mphComparison page for 225/75R15 vs 225/70R16
225/65R1728.52 in+0.81%60.48 mphComparison page for 225/75R15 vs 225/65R17
235/65R1628.03 in-0.92%59.45 mphComparison page for 225/75R15 vs 235/65R16
215/65R1728.00 in-1.00%59.40 mphNo comparison page

For a size without a comparison page, open 225/75R15 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 225/75R15 as the current tire and 225/70R16, the published comparison closest in overall diameter, as the proposed tire. Change either size; wheel details stay unknown until you supply them.

Compare 225/75R15 with 225/70R16 in the calculator

Compare 225/75R15 with any size

3 of 8 keep the 15-inch rim. Diameter changes are measured from 225/75R15.

Same 15-inch rim

Larger wheels (plus sizing)

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.