235/55R20 tire size
A 235/55R20 tire is 30.18 inches (766.5 mm) tall, 9.25 in (235 mm) wide and fits a 20-inch wheel. In inch notation it is roughly a 30.2x9.3R20 — a "30-inch" tire.
| Overall diameter | 30.18 in | 766.5 mm |
|---|---|---|
| Section width | 9.25 in | 235 mm |
| Sidewall height | 5.09 in | 129.3 mm |
| Circumference | 94.80 in | 2,408 mm |
| Revolutions | 668.3 per mile | 415.3 per km |
| Rim diameter | 20 in | 508.0 mm |
Compare 235/55R20 with another size
Alternative sizes on the same 20-inch wheel
Sizes in use within ±3 % of the overall diameter of 235/55R20:
Plus and minus sizes for 235/55R20
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 255/60R18 | Minus 2 (18 in) | 30.05 in | −0.43% |
| 235/65R18 | Minus 2 (18 in) | 30.03 in | −0.50% |
| 285/55R18 | Minus 2 (18 in) | 30.34 in | +0.55% |
| 265/60R18 | Minus 2 (18 in) | 30.52 in | +1.14% |
| 235/60R19 | Minus 1 (19 in) | 30.10 in | −0.25% |
| 255/55R19 | Minus 1 (19 in) | 30.04 in | −0.44% |
| 265/55R19 | Minus 1 (19 in) | 30.48 in | +0.99% |
| 275/50R19 | Minus 1 (19 in) | 29.83 in | −1.16% |
| 235/50R21 | Plus 1 (21 in) | 30.25 in | +0.25% |
| 255/45R21 | Plus 1 (21 in) | 30.04 in | −0.47% |
| 285/40R21 | Plus 1 (21 in) | 29.98 in | −0.67% |
| 265/45R21 | Plus 1 (21 in) | 30.39 in | +0.70% |
| 255/40R22 | Plus 2 (22 in) | 30.03 in | −0.48% |
| 265/40R22 | Plus 2 (22 in) | 30.35 in | +0.56% |
| 285/35R22 | Plus 2 (22 in) | 29.85 in | −1.07% |
| 275/40R22 | Plus 2 (22 in) | 30.66 in | +1.60% |
| 275/35R23 | Plus 3 (23 in) | 30.58 in | +1.33% |
| 285/35R23 | Plus 3 (23 in) | 30.85 in | +2.24% |
| 255/40R23 | Plus 3 (23 in) | 31.03 in | +2.83% |
Vehicles approved with 235/55R20 tires
Models whose Swiss type approval lists 235/55R20 as a standard or optional size (53 approvals in total). Always check your own vehicle's placard or papers.
Source: Swiss Federal Roads Office (FEDRO/ASTRA), open government data. Original data (downloaded 2026-09-29). Data processed by us; errors in processing are ours, not the publisher's.
Nearby 20-inch sizes
Reading the 235/55R20 size
- 235 — section width in millimetres (9.25 in).
- 55 — aspect ratio: the sidewall is 55 % of the width, 129.3 mm.
- R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
- 20 — fits a 20-inch diameter wheel.
The load index and speed rating (for example 91V) follow the size on the sidewall. They must meet at least the values on your vehicle's tire placard.