255/55R18 tire size
A 255/55R18 tire is 29.04 inches (737.7 mm) tall, 10.04 in (255 mm) wide and fits a 18-inch wheel. In inch notation it is roughly a 29.0x10.0R18 — a "29-inch" tire.
| Overall diameter | 29.04 in | 737.7 mm |
|---|---|---|
| Section width | 10.04 in | 255 mm |
| Sidewall height | 5.52 in | 140.3 mm |
| Circumference | 91.24 in | 2,318 mm |
| Revolutions | 694.4 per mile | 431.5 per km |
| Rim diameter | 18 in | 457.2 mm |
Compare 255/55R18 with another size
Alternative sizes on the same 18-inch wheel
Sizes in use within ±3 % of the overall diameter of 255/55R18:
Plus and minus sizes for 255/55R18
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 255/65R16 | Minus 2 (16 in) | 29.05 in | +0.03% |
| 235/70R16 | Minus 2 (16 in) | 28.95 in | −0.31% |
| 225/75R16 | Minus 2 (16 in) | 29.29 in | +0.84% |
| 245/70R16 | Minus 2 (16 in) | 29.50 in | +1.59% |
| 255/60R17 | Minus 1 (17 in) | 29.05 in | +0.01% |
| 235/65R17 | Minus 1 (17 in) | 29.03 in | −0.05% |
| 275/55R17 | Minus 1 (17 in) | 28.91 in | −0.46% |
| 225/70R17 | Minus 1 (17 in) | 29.40 in | +1.23% |
| 255/50R19 | Plus 1 (19 in) | 29.04 in | −0.01% |
| 285/45R19 | Plus 1 (19 in) | 29.10 in | +0.19% |
| 235/55R19 | Plus 1 (19 in) | 29.18 in | +0.46% |
| 275/45R19 | Plus 1 (19 in) | 28.74 in | −1.03% |
| 255/45R20 | Plus 2 (20 in) | 29.04 in | −0.03% |
| 285/40R20 | Plus 2 (20 in) | 28.98 in | −0.23% |
| 235/50R20 | Plus 2 (20 in) | 29.25 in | +0.72% |
| 295/40R20 | Plus 2 (20 in) | 29.29 in | +0.85% |
| 255/40R21 | Plus 3 (21 in) | 29.03 in | −0.04% |
| 295/35R21 | Plus 3 (21 in) | 29.13 in | +0.30% |
| 285/35R21 | Plus 3 (21 in) | 28.85 in | −0.65% |
| 235/45R21 | Plus 3 (21 in) | 29.33 in | +0.98% |
Vehicles approved with 255/55R18 tires
Models whose Swiss type approval lists 255/55R18 as a standard or optional size (889 approvals in total). Always check your own vehicle's placard or papers.
- BMW X5
- Porsche Macan
- Volkswagen Touareg
- Porsche Cayenne
- Audi A6
- Audi Q7
- Mercedes-Benz ML
- Mercedes-Benz R-Class
- Mercedes-Benz GLE
- Audi A7
- Land Rover Range Rover
- Puch G
- Cadillac SRX
- Land Rover Discovery
- Mercedes-Benz G-Class
- Volkswagen ID
- Lexus RZ450E
- Mercedes-Benz S-Class
- Land Rover Range Rover Sport
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
- 235/45R18 (−9.4%)
- 235/50R18 (−6.2%)
- 235/55R18 (−3.0%)
- 235/60R18 (+0.2%)
- 235/65R18 (+3.4%)
- 245/45R18 (−8.1%)
- 245/50R18 (−4.8%)
- 245/60R18 (+1.8%)
- 245/65R18 (+5.2%)
- 255/45R18 (−6.9%)
- 255/50R18 (−3.5%)
- 255/60R18 (+3.5%)
- 255/65R18 (+6.9%)
- 265/45R18 (−5.7%)
- 265/60R18 (+5.1%)
- 265/65R18 (+8.7%)
- 275/45R18 (−4.5%)
- 275/60R18 (+6.7%)
- 275/65R18 (+10.4%)
Reading the 255/55R18 size
- 255 — section width in millimetres (10.04 in).
- 55 — aspect ratio: the sidewall is 55 % of the width, 140.3 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.