TireSizeCheck

275/45R20

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 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% · Good fit

275/45R20 → 255/45R20

255/45R20

Diameter +2.4% · Good fit

245/50R20 → 275/45R20

245/50R20

Diameter −0.3% · Good fit

255/50R20 → 275/45R20

255/50R20

Diameter +1.0% · Good fit

265/45R20 → 275/45R20

265/45R20

Diameter −1.2% · Good fit

265/50R20 → 275/45R20

265/50R20

Diameter +2.3% · Good fit

255/45R20 → 275/45R20

255/45R20

Diameter −2.4% · Good fit

275/40R20 → 275/45R20

275/40R20

Diameter −3.6% · Marginal fit — proceed with care

245/45R20 → 275/45R20

245/45R20

Diameter −3.6% · Marginal fit — proceed with care

255/55R20 → 275/45R20

255/55R20

Diameter +4.4% · Marginal fit — proceed with care

285/50R20 → 275/45R20

285/50R20

Diameter +5.0% · Marginal fit — proceed with care

295/35R20 → 275/45R20

295/35R20

Diameter −5.4% · Not recommended

245/55R19 → 275/45R20

245/55R19

Diameter −0.5% · Good fit

245/60R18 → 275/45R20

245/60R18

Diameter −0.6% · Good fit

285/40R21 → 275/45R20

285/40R21

Diameter +0.8% · Good fit

235/65R18 → 275/45R20

235/65R18

Diameter +1.0% · Good fit

275/45R20 → 235/65R18

235/65R18

Diameter −0.9% · Good fit

275/45R20 → 245/55R19

245/55R19

Diameter +0.5% · Good fit

275/45R20 → 245/45R20

245/45R20

Diameter +3.7% · Marginal fit — proceed with care

275/45R20 → 245/50R20

245/50R20

Diameter +0.3% · Good fit

275/45R20 → 255/50R20

255/50R20

Diameter −1.0% · Good fit

275/45R20 → 255/55R20

255/55R20

Diameter −4.2% · Marginal fit — proceed with care

275/45R20 → 265/45R20

265/45R20

Diameter +1.2% · Good fit

275/45R20 → 265/50R20

265/50R20

Diameter −2.3% · Good fit

275/45R20 → 275/40R20

275/40R20

Diameter +3.8% · Marginal fit — proceed with care

275/45R20 → 285/50R20

285/50R20

Diameter −4.7% · Marginal fit — proceed with care

275/45R20 → 265/40R21

265/40R21

Diameter +1.4% · Good fit

275/45R20 → 265/45R21

265/45R21

Diameter −2.1% · Good fit

275/45R20 → 275/45R21

275/45R21

Diameter −3.3% · Marginal fit — proceed with care

275/45R20 → 285/40R21

285/40R21

Diameter −0.8% · Good fit

275/45R20 → 275/40R22

275/40R22

Diameter −3.0% · Good fit

275/45R20 → 275/55R20

275/55R20

Diameter −6.8% · Not recommended

Common questions

What is the overall diameter of a 275/45R20 tire?
A 275/45R20 tire is about 29.74″ (756 mm) in overall diameter, with a sidewall height of 123.8 mm and a circumference of 93.44″.
How many revolutions per mile does a 275/45R20 tire turn?
A 275/45R20 turns roughly 678 revolutions per mile (421 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
What do the numbers in 275/45R20 mean?
275 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 275 × 45% = 123.8 mm tall.