TireSizeCheck

275/45R20

A 275/45R20 tire is 29.74 inches tall and 10.8 inches wide, with a 4.87-inch sidewall, mounted on a 20-inch wheel.

Common fitments: Tahoe, Expedition, Grand Cherokee

Overall diameter

29.74″

756 mm

Sidewall height

4.87″

123.8 mm

Tread width

275 mm

10.8″

Circumference

93.44″

7.8 ft

Revs per mile

678

421 per km

Wheel diameter

20″

aspect ratio 45%

Cross-section

Overall diameter
29.74″
Sidewall (each side)
4.87″
Wheel
20″

275/45R20 in inches and millimeters

Every dimension of a 275/45R20, converted both ways. Calculated from the size code, accurate to about 1%.

Measurement Inches Millimeters
Overall diameter (height) 29.74″ 756 mm
Tread width 10.8″ 275 mm
Sidewall height 4.87″ 123.8 mm
Wheel diameter 20″ 508 mm
Circumference 93.44″ 2373 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.

275/45R20 compared with other sizes

All 32 practical swaps involving 275/45R20 — diameter change, speedometer impact and a fit verdict for each.

275/45R20 → 265/50R19

265/50R19

Diameter +1.1% · This fits

275/45R20 → 255/45R20

255/45R20

Diameter +2.4% · This fits

245/50R20 → 275/45R20

245/50R20

Diameter −0.3% · This fits

255/50R20 → 275/45R20

255/50R20

Diameter +1.0% · This fits

265/45R20 → 275/45R20

265/45R20

Diameter −1.2% · This fits

265/50R20 → 275/45R20

265/50R20

Diameter +2.3% · This fits

255/45R20 → 275/45R20

255/45R20

Diameter −2.4% · This fits

275/40R20 → 275/45R20

275/40R20

Diameter −3.6% · Borderline. Check clearance first

245/45R20 → 275/45R20

245/45R20

Diameter −3.6% · Borderline. Check clearance first

255/55R20 → 275/45R20

255/55R20

Diameter +4.4% · Borderline. Check clearance first

285/50R20 → 275/45R20

285/50R20

Diameter +5.0% · Borderline. Check clearance first

295/35R20 → 275/45R20

295/35R20

Diameter −5.4% · Too big a jump

245/55R19 → 275/45R20

245/55R19

Diameter −0.5% · This fits

245/60R18 → 275/45R20

245/60R18

Diameter −0.6% · This fits

285/40R21 → 275/45R20

285/40R21

Diameter +0.8% · This fits

235/65R18 → 275/45R20

235/65R18

Diameter +1.0% · This fits

275/45R20 → 235/65R18

235/65R18

Diameter −0.9% · This fits

275/45R20 → 245/55R19

245/55R19

Diameter +0.5% · This fits

275/45R20 → 245/45R20

245/45R20

Diameter +3.7% · Borderline. Check clearance first

275/45R20 → 245/50R20

245/50R20

Diameter +0.3% · This fits

275/45R20 → 255/50R20

255/50R20

Diameter −1.0% · This fits

275/45R20 → 255/55R20

255/55R20

Diameter −4.2% · Borderline. Check clearance first

275/45R20 → 265/45R20

265/45R20

Diameter +1.2% · This fits

275/45R20 → 265/50R20

265/50R20

Diameter −2.3% · This fits

275/45R20 → 275/40R20

275/40R20

Diameter +3.8% · Borderline. Check clearance first

275/45R20 → 285/50R20

285/50R20

Diameter −4.7% · Borderline. Check clearance first

275/45R20 → 265/40R21

265/40R21

Diameter +1.4% · This fits

275/45R20 → 265/45R21

265/45R21

Diameter −2.1% · This fits

275/45R20 → 275/45R21

275/45R21

Diameter −3.3% · Borderline. Check clearance first

275/45R20 → 285/40R21

285/40R21

Diameter −0.8% · This fits

275/45R20 → 275/40R22

275/40R22

Diameter −3.0% · This fits

275/45R20 → 275/55R20

275/55R20

Diameter −6.8% · Too big a jump

Common questions

What is 275/45R20 in inches?
A 275/45R20 tire is 29.74 inches tall and 10.8 inches wide, with a 4.87-inch sidewall, mounted on a 20-inch wheel. In metric that is 756 mm tall and 275 mm wide. The circumference is 93.44 inches.
How tall is a 275/45R20 tire?
29.74 inches, or 756 mm. That is the overall diameter, wheel included. It turns about 678 times per mile, which is what your speedometer counts.
What do the numbers in 275/45R20 mean?
275 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 275 × 45% = 123.8 mm tall.