TireSizeCheck

275/40R20

A 275/40R20 tire is 28.66 inches tall and 10.8 inches wide, with a 4.33-inch sidewall, mounted on a 20-inch wheel.

Overall diameter

28.66″

728 mm

Sidewall height

4.33″

110.0 mm

Tread width

275 mm

10.8″

Circumference

90.04″

7.5 ft

Revs per mile

704

437 per km

Wheel diameter

20″

aspect ratio 40%

Cross-section

Overall diameter
28.66″
Sidewall (each side)
4.33″
Wheel
20″

275/40R20 in inches and millimeters

Every dimension of a 275/40R20, converted both ways. Calculated from the size code, accurate to about 1%.

Measurement Inches Millimeters
Overall diameter (height) 28.66″ 728 mm
Tread width 10.8″ 275 mm
Sidewall height 4.33″ 110.0 mm
Wheel diameter 20″ 508 mm
Circumference 90.04″ 2287 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.

275/40R20 compared with other sizes

All 26 practical swaps involving 275/40R20 — diameter change, speedometer impact and a fit verdict for each.

275/40R20 → 255/45R20

255/45R20

Diameter −1.3% · This fits

275/40R20 → 275/45R20

275/45R20

Diameter −3.6% · Borderline. Check clearance first

275/40R20 → 295/35R20

295/35R20

Diameter +1.9% · This fits

275/40R20 → 245/40R20

245/40R20

Diameter +3.4% · Borderline. Check clearance first

275/40R20 → 245/45R20

245/45R20

Diameter −0.1% · This fits

275/40R20 → 245/50R20

245/50R20

Diameter −3.3% · Borderline. Check clearance first

275/40R20 → 255/50R20

255/50R20

Diameter −4.6% · Borderline. Check clearance first

275/40R20 → 265/35R20

265/35R20

Diameter +5.0% · Borderline. Check clearance first

275/40R20 → 265/45R20

265/45R20

Diameter −2.5% · This fits

275/40R20 → 275/35R20

275/35R20

Diameter +3.9% · Borderline. Check clearance first

245/45R20 → 275/40R20

245/45R20

Diameter +0.1% · This fits

255/45R20 → 275/40R20

255/45R20

Diameter +1.3% · This fits

295/35R20 → 275/40R20

295/35R20

Diameter −1.9% · This fits

275/35R20 → 275/40R20

275/35R20

Diameter −3.8% · Borderline. Check clearance first

275/45R20 → 275/40R20

275/45R20

Diameter +3.8% · Borderline. Check clearance first

265/45R20 → 275/40R20

265/45R20

Diameter +2.5% · This fits

245/40R20 → 275/40R20

245/40R20

Diameter −3.3% · Borderline. Check clearance first

245/50R20 → 275/40R20

245/50R20

Diameter +3.4% · Borderline. Check clearance first

265/35R20 → 275/40R20

265/35R20

Diameter −4.7% · Borderline. Check clearance first

255/50R20 → 275/40R20

255/50R20

Diameter +4.8% · Borderline. Check clearance first

255/50R19 → 275/40R20

255/50R19

Diameter +1.3% · This fits

255/55R18 → 275/40R20

255/55R18

Diameter +1.3% · This fits

235/50R19 → 275/40R20

235/50R19

Diameter −1.4% · This fits

235/60R18 → 275/40R20

235/60R18

Diameter +1.5% · This fits

275/40R20 → 265/40R21

265/40R21

Diameter −2.3% · This fits

275/40R20 → 275/55R20

275/55R20

Diameter −10.2% · Too big a jump

Common questions

What is 275/40R20 in inches?
A 275/40R20 tire is 28.66 inches tall and 10.8 inches wide, with a 4.33-inch sidewall, mounted on a 20-inch wheel. In metric that is 728 mm tall and 275 mm wide. The circumference is 90.04 inches.
How tall is a 275/40R20 tire?
28.66 inches, or 728 mm. That is the overall diameter, wheel included. It turns about 704 times per mile, which is what your speedometer counts.
What do the numbers in 275/40R20 mean?
275 is the tread width in millimeters, 40 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 × 40% = 110.0 mm tall.