305/40R22 tire size
A 305/40R22 tire is 31.61 inches (802.8 mm) tall, 12.01 in (305 mm) wide and fits a 22-inch wheel. In inch notation it is roughly a 31.6x12.0R22 — a "32-inch" tire.
| Overall diameter | 31.61 in | 802.8 mm |
|---|---|---|
| Section width | 12.01 in | 305 mm |
| Sidewall height | 4.80 in | 122.0 mm |
| Circumference | 99.29 in | 2,522 mm |
| Revolutions | 638.1 per mile | 396.5 per km |
| Rim diameter | 22 in | 558.8 mm |
Compare 305/40R22 with another size
Alternative sizes on the same 22-inch wheel
Sizes in use within ±3 % of the overall diameter of 305/40R22:
Plus and minus sizes for 305/40R22
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 275/55R20 | Minus 2 (20 in) | 31.91 in | +0.96% |
| 285/50R20 | Minus 2 (20 in) | 31.22 in | −1.22% |
| 285/55R20 | Minus 2 (20 in) | 32.34 in | +2.33% |
| 275/50R20 | Minus 2 (20 in) | 30.83 in | −2.47% |
| 275/50R21 | Minus 1 (21 in) | 31.83 in | +0.70% |
| 325/40R21 | Minus 1 (21 in) | 31.24 in | −1.17% |
| 285/45R21 | Minus 1 (21 in) | 31.10 in | −1.61% |
| 315/40R21 | Minus 1 (21 in) | 30.92 in | −2.17% |
| 275/40R23 | Plus 1 (23 in) | 31.66 in | +0.17% |
| 305/35R23 | Plus 1 (23 in) | 31.41 in | −0.64% |
| 325/35R23 | Plus 1 (23 in) | 31.96 in | +1.11% |
| 285/40R23 | Plus 1 (23 in) | 31.98 in | +1.17% |
Vehicles approved with 305/40R22 tires
Models whose Swiss type approval lists 305/40R22 as a standard or optional size (5 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 22-inch sizes
Reading the 305/40R22 size
- 305 — section width in millimetres (12.01 in).
- 40 — aspect ratio: the sidewall is 40 % of the width, 122.0 mm.
- R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
- 22 — fits a 22-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.