245/45R18
Common fitments: Charger, Camaro, ES 350
Overall diameter
26.68″
678 mm
Sidewall height
4.34″
110.3 mm
Tread width
245 mm
9.6″
Circumference
83.82″
7.0 ft
Revs per mile
756
470 per km
Wheel diameter
18″
aspect ratio 45%
Cross-section
- Overall diameter
- 26.68″
- Sidewall (each side)
- 4.34″
- Wheel
- 18″
245/45R18 compared with other sizes
All 31 practical swaps involving 245/45R18 — diameter change, speedometer impact and a fit verdict for each.
245/45R18 → 215/65R16
215/65R16
Diameter −1.2% · Good fit
245/45R18 → 225/60R16
225/60R16
Diameter +0.2% · Good fit
245/45R18 → 235/60R16
235/60R16
Diameter −1.6% · Good fit
245/45R18 → 225/55R17
225/55R17
Diameter −0.2% · Good fit
245/45R18 → 225/45R18
225/45R18
Diameter +2.7% · Good fit
245/45R18 → 235/40R18
235/40R18
Diameter +5.0% · Not recommended
245/45R18 → 235/45R18
235/45R18
Diameter +1.3% · Good fit
245/45R18 → 235/50R18
235/50R18
Diameter −2.1% · Good fit
245/45R18 → 245/40R18
245/40R18
Diameter +3.8% · Marginal fit — proceed with care
255/45R18 → 245/45R18
255/45R18
Diameter +1.3% · Good fit
235/45R18 → 245/45R18
235/45R18
Diameter −1.3% · Good fit
235/50R18 → 245/45R18
235/50R18
Diameter +2.1% · Good fit
245/40R18 → 245/45R18
245/40R18
Diameter −3.6% · Marginal fit — proceed with care
255/40R18 → 245/45R18
255/40R18
Diameter −2.4% · Good fit
225/45R18 → 245/45R18
225/45R18
Diameter −2.7% · Good fit
245/40R19 → 245/45R18
245/40R19
Diameter +0.1% · Good fit
245/35R20 → 245/45R18
245/35R20
Diameter +0.3% · Good fit
235/40R18 → 245/45R18
235/40R18
Diameter −4.8% · Marginal fit — proceed with care
225/60R16 → 245/45R18
225/60R16
Diameter −0.2% · Good fit
225/55R17 → 245/45R18
225/55R17
Diameter +0.2% · Good fit
205/65R16 → 245/45R18
205/65R16
Diameter −0.7% · Good fit
235/40R19 → 245/45R18
235/40R19
Diameter −1.0% · Good fit
215/65R16 → 245/45R18
215/65R16
Diameter +1.2% · Good fit
245/45R18 → 235/40R19
235/40R19
Diameter +1.1% · Good fit
245/45R18 → 245/40R19
245/40R19
Diameter −0.1% · Good fit
245/45R18 → 245/35R20
245/35R20
Diameter −0.3% · Good fit
245/45R18 → 255/35R20
255/35R20
Diameter −1.3% · Good fit
245/45R18 → 205/65R16
205/65R16
Diameter +0.7% · Good fit
245/45R18 → 235/55R18
235/55R18
Diameter −5.3% · Not recommended
245/45R18 → 255/40R18
255/40R18
Diameter +2.5% · Good fit
245/45R18 → 255/45R18
255/45R18
Diameter −1.3% · Good fit
Common questions
- What is the overall diameter of a 245/45R18 tire?
- A 245/45R18 tire is about 26.68″ (678 mm) in overall diameter, with a sidewall height of 110.3 mm and a circumference of 83.82″.
- How many revolutions per mile does a 245/45R18 tire turn?
- A 245/45R18 turns roughly 756 revolutions per mile (470 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
- What do the numbers in 245/45R18 mean?
- 245 is the tread width in millimetres, 45 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 245 × 45% = 110.3 mm tall.