235/65R18
Overall diameter
30.03″
763 mm
Sidewall height
6.01″
152.8 mm
Tread width
235 mm
9.3″
Circumference
94.33″
7.9 ft
Revs per mile
672
417 per km
Wheel diameter
18″
aspect ratio 65%
Cross-section
- Overall diameter
- 30.03″
- Sidewall (each side)
- 6.01″
- Wheel
- 18″
235/65R18 compared with other sizes
All 30 practical swaps involving 235/65R18 — diameter change, speedometer impact and a fit verdict for each.
235/65R18 → 245/75R16
245/75R16
Diameter −1.4% · Good fit
235/65R18 → 235/60R18
235/60R18
Diameter +3.2% · Marginal fit — proceed with care
235/65R18 → 255/55R18
255/55R18
Diameter +3.4% · Marginal fit — proceed with care
235/65R18 → 265/60R18
265/60R18
Diameter −1.6% · Good fit
235/65R18 → 275/45R20
275/45R20
Diameter +1.0% · Good fit
235/65R18 → 245/70R16
245/70R16
Diameter +1.8% · Good fit
235/65R18 → 255/70R16
255/70R16
Diameter −0.1% · Good fit
235/65R18 → 255/65R17
255/65R17
Diameter −0.1% · Good fit
235/65R18 → 225/60R18
225/60R18
Diameter +4.9% · Marginal fit — proceed with care
255/60R18 → 235/65R18
255/60R18
Diameter +0.1% · Good fit
245/60R18 → 235/65R18
245/60R18
Diameter −1.5% · Good fit
265/60R18 → 235/65R18
265/60R18
Diameter +1.6% · Good fit
245/65R18 → 235/65R18
245/65R18
Diameter +1.7% · Good fit
235/60R18 → 235/65R18
235/60R18
Diameter −3.1% · Marginal fit — proceed with care
275/60R18 → 235/65R18
275/60R18
Diameter +3.2% · Marginal fit — proceed with care
255/55R18 → 235/65R18
255/55R18
Diameter −3.3% · Marginal fit — proceed with care
255/65R18 → 235/65R18
255/65R18
Diameter +3.4% · Marginal fit — proceed with care
225/60R18 → 235/65R18
225/60R18
Diameter −4.7% · Marginal fit — proceed with care
255/50R20 → 235/65R18
255/50R20
Diameter +0.0% · Good fit
255/65R17 → 235/65R18
255/65R17
Diameter +0.1% · Good fit
255/70R16 → 235/65R18
255/70R16
Diameter +0.1% · Good fit
265/65R18 → 235/65R18
265/65R18
Diameter +5.1% · Not recommended
275/45R20 → 235/65R18
275/45R20
Diameter −0.9% · Good fit
235/65R18 → 245/60R18
245/60R18
Diameter +1.5% · Good fit
235/65R18 → 245/65R18
245/65R18
Diameter −1.7% · Good fit
235/65R18 → 255/60R18
255/60R18
Diameter −0.1% · Good fit
235/65R18 → 255/65R18
255/65R18
Diameter −3.3% · Marginal fit — proceed with care
235/65R18 → 275/60R18
275/60R18
Diameter −3.1% · Marginal fit — proceed with care
235/65R18 → 255/50R20
255/50R20
Diameter −0.0% · Good fit
235/65R18 → 235/45R18
235/45R18
Diameter +14.1% · Not recommended
Common questions
- What is the overall diameter of a 235/65R18 tire?
- A 235/65R18 tire is about 30.03″ (763 mm) in overall diameter, with a sidewall height of 152.8 mm and a circumference of 94.33″.
- How many revolutions per mile does a 235/65R18 tire turn?
- A 235/65R18 turns roughly 672 revolutions per mile (417 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
- What do the numbers in 235/65R18 mean?
- 235 is the tread width in millimetres, 65 is the aspect ratio — the sidewall height as a percentage of the tread width — and 18 is the wheel diameter in inches. So the sidewall is 235 × 65% = 152.8 mm tall.