245/45R20
Overall diameter
28.68″
729 mm
Sidewall height
4.34″
110.3 mm
Tread width
245 mm
9.6″
Circumference
90.10″
7.5 ft
Revs per mile
703
437 per km
Wheel diameter
20″
aspect ratio 45%
Cross-section
- Overall diameter
- 28.68″
- Sidewall (each side)
- 4.34″
- Wheel
- 20″
245/45R20 compared with other sizes
All 26 practical swaps involving 245/45R20 — diameter change, speedometer impact and a fit verdict for each.
245/45R20 → 255/45R20
255/45R20
Diameter −1.2% · Good fit
245/45R20 → 275/45R20
275/45R20
Diameter −3.6% · Marginal fit — proceed with care
245/45R20 → 225/60R18
225/60R18
Diameter +0.2% · Good fit
245/45R20 → 245/40R20
245/40R20
Diameter +3.5% · Marginal fit — proceed with care
275/40R20 → 245/45R20
275/40R20
Diameter −0.1% · Good fit
255/45R20 → 245/45R20
255/45R20
Diameter +1.2% · Good fit
245/40R20 → 245/45R20
245/40R20
Diameter −3.4% · Marginal fit — proceed with care
245/50R20 → 245/45R20
245/50R20
Diameter +3.4% · Marginal fit — proceed with care
265/45R20 → 245/45R20
265/45R20
Diameter +2.5% · Good fit
275/45R20 → 245/45R20
275/45R20
Diameter +3.7% · Marginal fit — proceed with care
275/35R20 → 245/45R20
275/35R20
Diameter −3.8% · Marginal fit — proceed with care
255/50R20 → 245/45R20
255/50R20
Diameter +4.7% · Marginal fit — proceed with care
265/35R20 → 245/45R20
265/35R20
Diameter −4.8% · Marginal fit — proceed with care
225/60R18 → 245/45R20
225/60R18
Diameter −0.2% · Good fit
255/50R19 → 245/45R20
255/50R19
Diameter +1.2% · Good fit
255/55R18 → 245/45R20
255/55R18
Diameter +1.3% · Good fit
235/60R18 → 245/45R20
235/60R18
Diameter +1.5% · Good fit
235/50R19 → 245/45R20
235/50R19
Diameter −1.5% · Good fit
245/45R20 → 245/50R20
245/50R20
Diameter −3.3% · Marginal fit — proceed with care
245/45R20 → 255/50R20
255/50R20
Diameter −4.5% · Marginal fit — proceed with care
245/45R20 → 265/35R20
265/35R20
Diameter +5.0% · Not recommended
245/45R20 → 265/45R20
265/45R20
Diameter −2.4% · Good fit
245/45R20 → 275/35R20
275/35R20
Diameter +4.0% · Marginal fit — proceed with care
245/45R20 → 275/40R20
275/40R20
Diameter +0.1% · Good fit
245/45R20 → 265/40R21
265/40R21
Diameter −2.3% · Good fit
245/45R20 → 275/55R20
275/55R20
Diameter −10.1% · Not recommended
Common questions
- What is the overall diameter of a 245/45R20 tire?
- A 245/45R20 tire is about 28.68″ (729 mm) in overall diameter, with a sidewall height of 110.3 mm and a circumference of 90.10″.
- How many revolutions per mile does a 245/45R20 tire turn?
- A 245/45R20 turns roughly 703 revolutions per mile (437 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
- What do the numbers in 245/45R20 mean?
- 245 is the tread width in millimetres, 45 is the aspect ratio — the sidewall height as a percentage of the tread width — and 20 is the wheel diameter in inches. So the sidewall is 245 × 45% = 110.3 mm tall.