255/55R18
Common fitments: Pilot, Explorer, Durango
Overall diameter
29.04″
738 mm
Sidewall height
5.52″
140.3 mm
Tread width
255 mm
10.0″
Circumference
91.24″
7.6 ft
Revs per mile
694
431 per km
Wheel diameter
18″
aspect ratio 55%
Cross-section
- Overall diameter
- 29.04″
- Sidewall (each side)
- 5.52″
- Wheel
- 18″
255/55R18 compared with other sizes
All 33 practical swaps involving 255/55R18 — diameter change, speedometer impact and a fit verdict for each.
255/55R18 → 235/60R18
235/60R18
Diameter −0.2% · Good fit
235/60R18 → 255/55R18
235/60R18
Diameter +0.2% · Good fit
225/60R18 → 255/55R18
225/60R18
Diameter −1.4% · Good fit
245/60R18 → 255/55R18
245/60R18
Diameter +1.8% · Good fit
255/60R18 → 255/55R18
255/60R18
Diameter +3.5% · Marginal fit — proceed with care
235/55R18 → 255/55R18
235/55R18
Diameter −3.0% · Good fit
235/65R18 → 255/55R18
235/65R18
Diameter +3.4% · Marginal fit — proceed with care
255/50R19 → 255/55R18
255/50R19
Diameter −0.0% · Good fit
255/45R20 → 255/55R18
255/45R20
Diameter −0.0% · Good fit
235/65R17 → 255/55R18
235/65R17
Diameter −0.1% · Good fit
265/60R18 → 255/55R18
265/60R18
Diameter +5.1% · Not recommended
245/65R18 → 255/55R18
245/65R18
Diameter +5.2% · Not recommended
235/70R16 → 255/55R18
235/70R16
Diameter −0.3% · Good fit
235/55R19 → 255/55R18
235/55R19
Diameter +0.5% · Good fit
225/75R16 → 255/55R18
225/75R16
Diameter +0.8% · Good fit
255/55R18 → 265/60R18
265/60R18
Diameter −4.8% · Marginal fit — proceed with care
255/55R18 → 255/45R20
255/45R20
Diameter +0.0% · Good fit
255/55R18 → 295/35R20
295/35R20
Diameter +3.2% · Marginal fit — proceed with care
255/55R18 → 225/75R16
225/75R16
Diameter −0.8% · Good fit
255/55R18 → 235/70R16
235/70R16
Diameter +0.3% · Good fit
255/55R18 → 245/70R16
245/70R16
Diameter −1.6% · Good fit
255/55R18 → 235/65R17
235/65R17
Diameter +0.1% · Good fit
255/55R18 → 225/60R18
225/60R18
Diameter +1.4% · Good fit
255/55R18 → 235/55R18
235/55R18
Diameter +3.1% · Marginal fit — proceed with care
255/55R18 → 235/65R18
235/65R18
Diameter −3.3% · Marginal fit — proceed with care
255/55R18 → 245/60R18
245/60R18
Diameter −1.8% · Good fit
255/55R18 → 245/65R18
245/65R18
Diameter −4.9% · Marginal fit — proceed with care
255/55R18 → 255/60R18
255/60R18
Diameter −3.3% · Marginal fit — proceed with care
255/55R18 → 235/55R19
235/55R19
Diameter −0.5% · Good fit
255/55R18 → 255/50R19
255/50R19
Diameter +0.0% · Good fit
255/55R18 → 245/45R20
245/45R20
Diameter +1.3% · Good fit
255/55R18 → 275/40R20
275/40R20
Diameter +1.3% · Good fit
255/55R18 → 235/45R18
235/45R18
Diameter +10.3% · Not recommended
Common questions
- What is the overall diameter of a 255/55R18 tire?
- A 255/55R18 tire is about 29.04″ (738 mm) in overall diameter, with a sidewall height of 140.3 mm and a circumference of 91.24″.
- How many revolutions per mile does a 255/55R18 tire turn?
- A 255/55R18 turns roughly 694 revolutions per mile (431 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
- What do the numbers in 255/55R18 mean?
- 255 is the tread width in millimetres, 55 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 255 × 55% = 140.3 mm tall.