245/45R20
A 245/45R20 tire is 28.68 inches tall and 9.6 inches wide, with a 4.34-inch sidewall, mounted on a 20-inch wheel.
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 in inches and millimeters
Every dimension of a 245/45R20, converted both ways. Calculated from the size code, accurate to about 1%.
| Measurement | Inches | Millimeters |
|---|---|---|
| Overall diameter (height) | 28.68″ | 729 mm |
| Tread width | 9.6″ | 245 mm |
| Sidewall height | 4.34″ | 110.3 mm |
| Wheel diameter | 20″ | 508 mm |
| Circumference | 90.10″ | 2289 mm |
Nominal dimensions from the size code. A real tire varies by a few millimeters between manufacturers, and a loaded tire sits slightly shorter than its free diameter.
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% · This fits
245/45R20 → 275/45R20
275/45R20
Diameter −3.6% · Borderline. Check clearance first
245/45R20 → 225/60R18
225/60R18
Diameter +0.2% · This fits
245/45R20 → 245/40R20
245/40R20
Diameter +3.5% · Borderline. Check clearance first
275/40R20 → 245/45R20
275/40R20
Diameter −0.1% · This fits
255/45R20 → 245/45R20
255/45R20
Diameter +1.2% · This fits
245/40R20 → 245/45R20
245/40R20
Diameter −3.4% · Borderline. Check clearance first
245/50R20 → 245/45R20
245/50R20
Diameter +3.4% · Borderline. Check clearance first
265/45R20 → 245/45R20
265/45R20
Diameter +2.5% · This fits
275/45R20 → 245/45R20
275/45R20
Diameter +3.7% · Borderline. Check clearance first
275/35R20 → 245/45R20
275/35R20
Diameter −3.8% · Borderline. Check clearance first
255/50R20 → 245/45R20
255/50R20
Diameter +4.7% · Borderline. Check clearance first
265/35R20 → 245/45R20
265/35R20
Diameter −4.8% · Borderline. Check clearance first
225/60R18 → 245/45R20
225/60R18
Diameter −0.2% · This fits
255/50R19 → 245/45R20
255/50R19
Diameter +1.2% · This fits
255/55R18 → 245/45R20
255/55R18
Diameter +1.3% · This fits
235/60R18 → 245/45R20
235/60R18
Diameter +1.5% · This fits
235/50R19 → 245/45R20
235/50R19
Diameter −1.5% · This fits
245/45R20 → 245/50R20
245/50R20
Diameter −3.3% · Borderline. Check clearance first
245/45R20 → 255/50R20
255/50R20
Diameter −4.5% · Borderline. Check clearance first
245/45R20 → 265/35R20
265/35R20
Diameter +5.0% · Too big a jump
245/45R20 → 265/45R20
265/45R20
Diameter −2.4% · This fits
245/45R20 → 275/35R20
275/35R20
Diameter +4.0% · Borderline. Check clearance first
245/45R20 → 275/40R20
275/40R20
Diameter +0.1% · This fits
245/45R20 → 265/40R21
265/40R21
Diameter −2.3% · This fits
245/45R20 → 275/55R20
275/55R20
Diameter −10.1% · Too big a jump
Common questions
- What is 245/45R20 in inches?
- A 245/45R20 tire is 28.68 inches tall and 9.6 inches wide, with a 4.34-inch sidewall, mounted on a 20-inch wheel. In metric that is 729 mm tall and 245 mm wide. The circumference is 90.10 inches.
- How tall is a 245/45R20 tire?
- 28.68 inches, or 729 mm. That is the overall diameter, wheel included. It turns about 703 times per mile, which is what your speedometer counts.
- What do the numbers in 245/45R20 mean?
- 245 is the tread width in millimeters, 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.