305/35R21 tire size
A 305/35R21 tire is 29.41 inches (746.9 mm) tall, 12.01 in (305 mm) wide and fits a 21-inch wheel. In inch notation it is roughly a 29.4x12.0R21 — a "29-inch" tire.
| Overall diameter | 29.41 in | 746.9 mm |
|---|---|---|
| Section width | 12.01 in | 305 mm |
| Sidewall height | 4.20 in | 106.8 mm |
| Circumference | 92.38 in | 2,346 mm |
| Revolutions | 685.9 per mile | 426.2 per km |
| Rim diameter | 21 in | 533.4 mm |
Compare 305/35R21 with another size
Alternative sizes on the same 21-inch wheel
Sizes in use within ±3 % of the overall diameter of 305/35R21:
Plus and minus sizes for 305/35R21
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 295/45R19 | Minus 2 (19 in) | 29.45 in | +0.16% |
| 285/45R19 | Minus 2 (19 in) | 29.10 in | −1.04% |
| 275/50R19 | Minus 2 (19 in) | 29.83 in | +1.43% |
| 275/45R19 | Minus 2 (19 in) | 28.74 in | −2.25% |
| 295/40R20 | Minus 1 (20 in) | 29.29 in | −0.39% |
| 305/40R20 | Minus 1 (20 in) | 29.61 in | +0.68% |
| 275/45R20 | Minus 1 (20 in) | 29.74 in | +1.15% |
| 285/40R20 | Minus 1 (20 in) | 28.98 in | −1.46% |
| 315/30R22 | Plus 1 (22 in) | 29.44 in | +0.12% |
| 275/35R22 | Plus 1 (22 in) | 29.58 in | +0.59% |
| 305/30R22 | Plus 1 (22 in) | 29.20 in | −0.68% |
| 355/25R22 | Plus 1 (22 in) | 28.99 in | −1.42% |
Vehicles approved with 305/35R21 tires
Models whose Swiss type approval lists 305/35R21 as a standard or optional size (119 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 305/35R21 size
- 305 — section width in millimetres (12.01 in).
- 35 — aspect ratio: the sidewall is 35 % of the width, 106.8 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.