245/55R21 tire size
A 245/55R21 tire is 31.61 inches (802.9 mm) tall, 9.65 in (245 mm) wide and fits a 21-inch wheel. In inch notation it is roughly a 31.6x9.6R21 — a "32-inch" tire.
| Overall diameter | 31.61 in | 802.9 mm |
|---|---|---|
| Section width | 9.65 in | 245 mm |
| Sidewall height | 5.31 in | 134.8 mm |
| Circumference | 99.31 in | 2,522 mm |
| Revolutions | 638.0 per mile | 396.5 per km |
| Rim diameter | 21 in | 533.4 mm |
Compare 245/55R21 with another size
Alternative sizes on the same 21-inch wheel
Sizes in use within ±3 % of the overall diameter of 245/55R21:
Plus and minus sizes for 245/55R21
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 255/65R19 | Minus 2 (19 in) | 32.05 in | +1.39% |
| 255/60R19 | Minus 2 (19 in) | 31.05 in | −1.78% |
| 235/65R19 | Minus 2 (19 in) | 31.03 in | −1.84% |
| 275/55R19 | Minus 2 (19 in) | 30.91 in | −2.22% |
| 275/55R20 | Minus 1 (20 in) | 31.91 in | +0.95% |
| 285/50R20 | Minus 1 (20 in) | 31.22 in | −1.23% |
| 255/60R20 | Minus 1 (20 in) | 32.05 in | +1.38% |
| 235/60R20 | Minus 1 (20 in) | 31.10 in | −1.61% |
| 275/45R22 | Plus 1 (22 in) | 31.74 in | +0.42% |
| 295/40R22 | Plus 1 (22 in) | 31.29 in | −1.01% |
| 285/45R22 | Plus 1 (22 in) | 32.10 in | +1.54% |
| 255/45R22 | Plus 1 (22 in) | 31.04 in | −1.82% |
| 275/40R23 | Plus 2 (23 in) | 31.66 in | +0.16% |
| 285/40R23 | Plus 2 (23 in) | 31.98 in | +1.16% |
| 295/35R23 | Plus 2 (23 in) | 31.13 in | −1.52% |
| 255/40R23 | Plus 2 (23 in) | 31.03 in | −1.83% |
Vehicles approved with 245/55R21 tires
Models whose Swiss type approval lists 245/55R21 as a standard or optional size (3 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 21-inch sizes
Reading the 245/55R21 size
- 245 — section width in millimetres (9.65 in).
- 55 — aspect ratio: the sidewall is 55 % of the width, 134.8 mm.
- R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
- 21 — fits a 21-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.