255/50R20
Common fitments: Grand Cherokee, Durango
Overall diameter
30.04″
763 mm
Sidewall height
5.02″
127.5 mm
Tread width
255 mm
10.0″
Circumference
94.37″
7.9 ft
Revs per mile
671
417 per km
Wheel diameter
20″
aspect ratio 50%
Cross-section
- Overall diameter
- 30.04″
- Sidewall (each side)
- 5.02″
- Wheel
- 20″
255/50R20 compared with other sizes
All 32 practical swaps involving 255/50R20 — diameter change, speedometer impact and a fit verdict for each.
255/50R20 → 255/45R20
255/45R20
Diameter +3.5% · Marginal fit — proceed with care
255/50R20 → 275/45R20
275/45R20
Diameter +1.0% · Good fit
255/50R20 → 235/65R18
235/65R18
Diameter +0.0% · Good fit
255/50R20 → 255/60R18
255/60R18
Diameter −0.0% · Good fit
255/50R20 → 245/45R20
245/45R20
Diameter +4.7% · Marginal fit — proceed with care
255/50R20 → 245/50R20
245/50R20
Diameter +1.3% · Good fit
275/45R20 → 255/50R20
275/45R20
Diameter −1.0% · Good fit
245/50R20 → 255/50R20
245/50R20
Diameter −1.3% · Good fit
265/50R20 → 255/50R20
265/50R20
Diameter +1.3% · Good fit
255/45R20 → 255/50R20
255/45R20
Diameter −3.3% · Marginal fit — proceed with care
255/55R20 → 255/50R20
255/55R20
Diameter +3.3% · Marginal fit — proceed with care
265/45R20 → 255/50R20
265/45R20
Diameter −2.2% · Good fit
255/60R18 → 255/50R20
255/60R18
Diameter +0.0% · Good fit
285/50R20 → 255/50R20
285/50R20
Diameter +3.9% · Marginal fit — proceed with care
245/45R20 → 255/50R20
245/45R20
Diameter −4.5% · Marginal fit — proceed with care
275/40R20 → 255/50R20
275/40R20
Diameter −4.6% · Marginal fit — proceed with care
265/55R20 → 255/50R20
265/55R20
Diameter +4.8% · Marginal fit — proceed with care
235/65R18 → 255/50R20
235/65R18
Diameter −0.0% · Good fit
285/40R21 → 255/50R20
285/40R21
Diameter −0.2% · Good fit
265/45R21 → 255/50R20
265/45R21
Diameter +1.2% · Good fit
255/50R20 → 255/55R20
255/55R20
Diameter −3.2% · Marginal fit — proceed with care
255/50R20 → 265/45R20
265/45R20
Diameter +2.2% · Good fit
255/50R20 → 265/50R20
265/50R20
Diameter −1.3% · Good fit
255/50R20 → 265/55R20
265/55R20
Diameter −4.6% · Marginal fit — proceed with care
255/50R20 → 275/40R20
275/40R20
Diameter +4.8% · Marginal fit — proceed with care
255/50R20 → 285/50R20
285/50R20
Diameter −3.8% · Marginal fit — proceed with care
255/50R20 → 265/40R21
265/40R21
Diameter +2.4% · Good fit
255/50R20 → 265/45R21
265/45R21
Diameter −1.2% · Good fit
255/50R20 → 285/40R21
285/40R21
Diameter +0.2% · Good fit
255/50R20 → 275/40R22
275/40R22
Diameter −2.0% · Good fit
255/50R20 → 285/40R22
285/40R22
Diameter −3.0% · Marginal fit — proceed with care
255/50R20 → 275/55R20
275/55R20
Diameter −5.9% · Not recommended
Common questions
- What is the overall diameter of a 255/50R20 tire?
- A 255/50R20 tire is about 30.04″ (763 mm) in overall diameter, with a sidewall height of 127.5 mm and a circumference of 94.37″.
- How many revolutions per mile does a 255/50R20 tire turn?
- A 255/50R20 turns roughly 671 revolutions per mile (417 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
- What do the numbers in 255/50R20 mean?
- 255 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 255 × 50% = 127.5 mm tall.