255/55R20 tire size
A 255/55R20 tire is 31.04 inches (788.5 mm) tall, 10.04 in (255 mm) wide and fits a 20-inch wheel. In inch notation it is roughly a 31.0x10.0R20 — a "31-inch" tire.
| Overall diameter | 31.04 in | 788.5 mm |
|---|---|---|
| Section width | 10.04 in | 255 mm |
| Sidewall height | 5.52 in | 140.3 mm |
| Circumference | 97.53 in | 2,477 mm |
| Revolutions | 649.7 per mile | 403.7 per km |
| Rim diameter | 20 in | 508.0 mm |
Compare 255/55R20 with another size
Alternative sizes on the same 20-inch wheel
Sizes in use within ±3 % of the overall diameter of 255/55R20:
Plus and minus sizes for 255/55R20
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 255/65R18 | Minus 2 (18 in) | 31.05 in | +0.03% |
| 275/60R18 | Minus 2 (18 in) | 30.99 in | −0.16% |
| 285/60R18 | Minus 2 (18 in) | 31.46 in | +1.36% |
| 245/65R18 | Minus 2 (18 in) | 30.54 in | −1.62% |
| 255/60R19 | Minus 1 (19 in) | 31.05 in | +0.01% |
| 235/65R19 | Minus 1 (19 in) | 31.03 in | −0.05% |
| 275/55R19 | Minus 1 (19 in) | 30.91 in | −0.43% |
| 265/55R19 | Minus 1 (19 in) | 30.48 in | −1.83% |
| 255/50R21 | Plus 1 (21 in) | 31.04 in | −0.01% |
| 285/45R21 | Plus 1 (21 in) | 31.10 in | +0.18% |
| 275/45R21 | Plus 1 (21 in) | 30.74 in | −0.96% |
| 305/40R21 | Plus 1 (21 in) | 30.61 in | −1.41% |
| 255/45R22 | Plus 2 (22 in) | 31.04 in | −0.03% |
| 285/40R22 | Plus 2 (22 in) | 30.98 in | −0.22% |
| 295/40R22 | Plus 2 (22 in) | 31.29 in | +0.80% |
| 275/40R22 | Plus 2 (22 in) | 30.66 in | −1.23% |
| 255/40R23 | Plus 3 (23 in) | 31.03 in | −0.04% |
| 295/35R23 | Plus 3 (23 in) | 31.13 in | +0.28% |
| 285/35R23 | Plus 3 (23 in) | 30.85 in | −0.61% |
| 305/35R23 | Plus 3 (23 in) | 31.41 in | +1.17% |
Vehicles approved with 255/55R20 tires
Models whose Swiss type approval lists 255/55R20 as a standard or optional size (671 approvals in total). Always check your own vehicle's placard or papers.
- BMW X7
- Land Rover Range Rover
- Land Rover Range Rover Sport
- Land Rover Discovery
- Porsche Cayenne
- Ford Explorer
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 255/55R20 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).
- 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.