285/55R18 tire size
A 285/55R18 tire is 30.34 inches (770.7 mm) tall, 11.22 in (285 mm) wide and fits a 18-inch wheel. In inch notation it is roughly a 30.3x11.2R18 — a "30-inch" tire.
| Overall diameter | 30.34 in | 770.7 mm |
|---|---|---|
| Section width | 11.22 in | 285 mm |
| Sidewall height | 6.17 in | 156.8 mm |
| Circumference | 95.32 in | 2,421 mm |
| Revolutions | 664.7 per mile | 413.0 per km |
| Rim diameter | 18 in | 457.2 mm |
Compare 285/55R18 with another size
Alternative sizes on the same 18-inch wheel
Sizes in use within ±3 % of the overall diameter of 285/55R18:
Plus and minus sizes for 285/55R18
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 265/70R16 | Minus 2 (16 in) | 30.61 in | +0.87% |
| 255/70R16 | Minus 2 (16 in) | 30.06 in | −0.95% |
| 275/70R16 | Minus 2 (16 in) | 31.16 in | +2.69% |
| 265/65R17 | Minus 1 (17 in) | 30.56 in | +0.73% |
| 255/65R17 | Minus 1 (17 in) | 30.05 in | −0.96% |
| 255/70R17 | Minus 1 (17 in) | 31.06 in | +2.35% |
| 275/65R17 | Minus 1 (17 in) | 31.07 in | +2.41% |
| 265/55R19 | Plus 1 (19 in) | 30.48 in | +0.44% |
| 255/55R19 | Plus 1 (19 in) | 30.04 in | −0.99% |
| 275/50R19 | Plus 1 (19 in) | 29.83 in | −1.70% |
| 275/55R19 | Plus 1 (19 in) | 30.91 in | +1.87% |
| 265/50R20 | Plus 2 (20 in) | 30.43 in | +0.30% |
| 295/45R20 | Plus 2 (20 in) | 30.45 in | +0.36% |
| 285/45R20 | Plus 2 (20 in) | 30.10 in | −0.80% |
| 255/50R20 | Plus 2 (20 in) | 30.04 in | −1.00% |
| 265/45R21 | Plus 3 (21 in) | 30.39 in | +0.16% |
| 295/40R21 | Plus 3 (21 in) | 30.29 in | −0.17% |
| 305/40R21 | Plus 3 (21 in) | 30.61 in | +0.87% |
| 255/45R21 | Plus 3 (21 in) | 30.04 in | −1.01% |
Vehicles approved with 285/55R18 tires
Models whose Swiss type approval lists 285/55R18 as a standard or optional size (7 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 18-inch sizes
Reading the 285/55R18 size
- 285 — section width in millimetres (11.22 in).
- 55 — aspect ratio: the sidewall is 55 % of the width, 156.8 mm.
- R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
- 18 — fits a 18-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.