Tire size in inches and millimeters

235/80R16 tire size in inches

A 235/80R16 tire is 30.80 inches tall (782.4 mm) and 9.25 inches wide (235 mm), with a 7.40-inch sidewall (188.0 mm). In inch notation that is about 30.8x9.3R16, close to a 31-inch tire (nominal).

Its circumference is 96.77 inches (2,458.0 mm), or about 655 revolutions per mile.

Nominal 235/80R16 dimensions

Overall diameter
30.80 in782.4 mm
Section width
9.25 in235 mm
Sidewall height
7.40 in188.0 mm
Circumference
96.77 in2,458.0 mm
Rim diameter
16 in
Revolutions per mile
655nominal, from geometric circumference
Inch notation
30.8x9.3R16approximate

Where 235/80R16 fits

  • Inch class: 30.80 in is 0.20 in short of a true 31 inches, inside the 31-inch class (30.50 to 31.49 in).
  • Profile: the 16-inch rim plus two 7.40 in sidewalls make up the overall diameter, and the sidewalls are 48% of it. At 80 series that is a very tall profile: the two sidewalls are close to half of the overall diameter.
  • Same 16-inch rim: the next taller catalog size is 255/75R16 (31.06 in, +0.83%) and the next shorter is 265/70R16 (30.61 in, -0.64%).
  • Same 235 mm width: the closest in diameter are 235/60R18 (29.10 in, -5.52%), 235/75R16 (29.88 in, -3.00%), 235/85R16 (31.73 in, +3.00%), 235/80R17 (31.80 in, +3.25%). 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, 80 is the sidewall height as a percentage of that width, and R16 means radial construction for a 16-inch rim. Percentages are measured from 235/80R16.

Similar sizes on other rim diameters

Within 3% of 235/80R16's overall diameter, nearest first. The speed column is the actual speed when a speedometer calibrated for 235/80R16 reads 60 mph.

Catalog tire sizes on other rim diameters with an overall diameter close to 235/80R16
SizeOverall diameterDiameter changeAt 60 mph indicatedCompare
265/75R1530.65 in-0.50%59.70 mphNo comparison page
265/65R1730.56 in-0.78%59.53 mphComparison page for 235/80R16 vs 265/65R17
255/65R1831.05 in+0.81%60.48 mphNo comparison page
255/70R1731.06 in+0.82%60.49 mphComparison page for 235/80R16 vs 255/70R17
265/60R1830.52 in-0.92%59.45 mphNo comparison page
245/70R1730.50 in-0.97%59.42 mphComparison page for 235/80R16 vs 245/70R17

For a size without a comparison page, open 235/80R16 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 235/80R16 as the current tire and 265/65R17, the published comparison closest in overall diameter, as the proposed tire. Change either size; wheel details stay unknown until you supply them.

Compare 235/80R16 with 265/65R17 in the calculator

Compare 235/80R16 with any size

3 of 7 keep the 16-inch rim. Diameter changes are measured from 235/80R16.

Same 16-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.