255/45R20
Common fitments: Model Y Performance, Edge
Overall diameter
29.04″
737 mm
Sidewall height
4.52″
114.8 mm
Tread width
255 mm
10.0″
Circumference
91.22″
7.6 ft
Revs per mile
695
432 per km
Wheel diameter
20″
aspect ratio 45%
Cross-section
- Overall diameter
- 29.04″
- Sidewall (each side)
- 4.52″
- Wheel
- 20″
255/45R20 compared with other sizes
All 30 practical swaps involving 255/45R20 — diameter change, speedometer impact and a fit verdict for each.
255/45R20 → 235/60R18
235/60R18
Diameter −0.2% · Good fit
255/45R20 → 255/55R18
255/55R18
Diameter −0.0% · Good fit
245/45R20 → 255/45R20
245/45R20
Diameter −1.2% · Good fit
265/45R20 → 255/45R20
265/45R20
Diameter +1.2% · Good fit
275/40R20 → 255/45R20
275/40R20
Diameter −1.3% · Good fit
245/50R20 → 255/45R20
245/50R20
Diameter +2.1% · Good fit
255/50R20 → 255/45R20
255/50R20
Diameter +3.5% · Marginal fit — proceed with care
275/45R20 → 255/45R20
275/45R20
Diameter +2.4% · Good fit
295/35R20 → 255/45R20
295/35R20
Diameter −3.1% · Marginal fit — proceed with care
255/50R19 → 255/45R20
255/50R19
Diameter +0.0% · Good fit
255/55R18 → 255/45R20
255/55R18
Diameter +0.0% · Good fit
245/40R20 → 255/45R20
245/40R20
Diameter −4.5% · Marginal fit — proceed with care
265/50R20 → 255/45R20
265/50R20
Diameter +4.8% · Marginal fit — proceed with care
275/35R20 → 255/45R20
275/35R20
Diameter −5.0% · Not recommended
235/60R18 → 255/45R20
235/60R18
Diameter +0.2% · Good fit
235/55R19 → 255/45R20
235/55R19
Diameter +0.5% · Good fit
255/45R20 → 275/45R20
275/45R20
Diameter −2.4% · Good fit
255/45R20 → 295/35R20
295/35R20
Diameter +3.2% · Marginal fit — proceed with care
255/45R20 → 235/55R19
235/55R19
Diameter −0.5% · Good fit
255/45R20 → 255/50R19
255/50R19
Diameter −0.0% · Good fit
255/45R20 → 245/40R20
245/40R20
Diameter +4.8% · Marginal fit — proceed with care
255/45R20 → 245/45R20
245/45R20
Diameter +1.2% · Good fit
255/45R20 → 245/50R20
245/50R20
Diameter −2.1% · Good fit
255/45R20 → 255/50R20
255/50R20
Diameter −3.3% · Marginal fit — proceed with care
255/45R20 → 265/45R20
265/45R20
Diameter −1.2% · Good fit
255/45R20 → 265/50R20
265/50R20
Diameter −4.6% · Marginal fit — proceed with care
255/45R20 → 275/35R20
275/35R20
Diameter +5.3% · Not recommended
255/45R20 → 275/40R20
275/40R20
Diameter +1.3% · Good fit
255/45R20 → 265/40R21
265/40R21
Diameter −1.1% · Good fit
255/45R20 → 275/55R20
275/55R20
Diameter −9.0% · Not recommended
Common questions
- What is the overall diameter of a 255/45R20 tire?
- A 255/45R20 tire is about 29.04″ (737 mm) in overall diameter, with a sidewall height of 114.8 mm and a circumference of 91.22″.
- How many revolutions per mile does a 255/45R20 tire turn?
- A 255/45R20 turns roughly 695 revolutions per mile (432 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
- What do the numbers in 255/45R20 mean?
- 255 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 255 × 45% = 114.8 mm tall.