TireSizeCheck

285/50R20

Overall diameter

31.22″

793 mm

Sidewall height

5.61″

142.5 mm

Tread width

285 mm

11.2″

Circumference

98.08″

8.2 ft

Revs per mile

646

401 per km

Wheel diameter

20″

aspect ratio 50%

Cross-section

Overall diameter
31.22″
Sidewall (each side)
5.61″
Wheel
20″

285/50R20 compared with other sizes

All 34 practical swaps involving 285/50R20 — diameter change, speedometer impact and a fit verdict for each.

285/50R20 → 275/45R20

275/45R20

Diameter +5.0% · Marginal fit — proceed with care

285/50R20 → 275/55R20

275/55R20

Diameter −2.2% · Good fit

285/50R20 → 285/60R18

285/60R18

Diameter −0.8% · Good fit

285/50R20 → 255/60R19

255/60R19

Diameter +0.6% · Good fit

285/50R20 → 275/55R19

275/55R19

Diameter +1.0% · Good fit

285/50R20 → 245/50R20

245/50R20

Diameter +5.3% · Not recommended

285/50R20 → 255/50R20

255/50R20

Diameter +3.9% · Marginal fit — proceed with care

285/50R20 → 255/55R20

255/55R20

Diameter +0.6% · Good fit

285/50R20 → 265/50R20

265/50R20

Diameter +2.6% · Good fit

285/50R20 → 265/55R20

265/55R20

Diameter −0.8% · Good fit

285/50R20 → 265/60R20

265/60R20

Diameter −4.0% · Marginal fit — proceed with care

285/50R20 → 275/60R20

275/60R20

Diameter −5.4% · Not recommended

255/55R20 → 285/50R20

255/55R20

Diameter −0.6% · Good fit

265/55R20 → 285/50R20

265/55R20

Diameter +0.8% · Good fit

275/55R20 → 285/50R20

275/55R20

Diameter +2.2% · Good fit

285/55R20 → 285/50R20

285/55R20

Diameter +3.6% · Marginal fit — proceed with care

265/50R20 → 285/50R20

265/50R20

Diameter −2.5% · Good fit

305/50R20 → 285/50R20

305/50R20

Diameter +2.5% · Good fit

255/50R20 → 285/50R20

255/50R20

Diameter −3.8% · Marginal fit — proceed with care

285/45R21 → 285/50R20

285/45R21

Diameter −0.4% · Good fit

265/60R20 → 285/50R20

265/60R20

Diameter +4.2% · Marginal fit — proceed with care

285/60R18 → 285/50R20

285/60R18

Diameter +0.8% · Good fit

285/40R22 → 285/50R20

285/40R22

Diameter −0.8% · Good fit

275/45R20 → 285/50R20

275/45R20

Diameter −4.7% · Marginal fit — proceed with care

245/50R20 → 285/50R20

245/50R20

Diameter −5.0% · Not recommended

255/65R18 → 285/50R20

255/65R18

Diameter −0.5% · Good fit

285/50R20 → 285/55R20

285/55R20

Diameter −3.5% · Marginal fit — proceed with care

285/50R20 → 305/50R20

305/50R20

Diameter −2.5% · Good fit

285/50R20 → 275/45R21

275/45R21

Diameter +1.5% · Good fit

285/50R20 → 275/50R21

275/50R21

Diameter −1.9% · Good fit

285/50R20 → 285/45R21

285/45R21

Diameter +0.4% · Good fit

285/50R20 → 275/40R22

275/40R22

Diameter +1.8% · Good fit

285/50R20 → 285/40R22

285/40R22

Diameter +0.8% · Good fit

285/50R20 → 285/45R22

285/45R22

Diameter −2.7% · Good fit

Common questions

What is the overall diameter of a 285/50R20 tire?
A 285/50R20 tire is about 31.22″ (793 mm) in overall diameter, with a sidewall height of 142.5 mm and a circumference of 98.08″.
How many revolutions per mile does a 285/50R20 tire turn?
A 285/50R20 turns roughly 646 revolutions per mile (401 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
What do the numbers in 285/50R20 mean?
285 is the tread width in millimetres, 50 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 285 × 50% = 142.5 mm tall.