315/30R20 tire size
A 315/30R20 tire is 27.44 inches (697.0 mm) tall, 12.40 in (315 mm) wide and fits a 20-inch wheel. In inch notation it is roughly a 27.4x12.4R20.
| Overall diameter | 27.44 in | 697.0 mm |
|---|---|---|
| Section width | 12.40 in | 315 mm |
| Sidewall height | 3.72 in | 94.5 mm |
| Circumference | 86.21 in | 2,190 mm |
| Revolutions | 735.0 per mile | 456.7 per km |
| Rim diameter | 20 in | 508.0 mm |
Compare 315/30R20 with another size
Alternative sizes on the same 20-inch wheel
Sizes in use within ±3 % of the overall diameter of 315/30R20:
Plus and minus sizes for 315/30R20
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 285/40R18 | Minus 2 (18 in) | 26.98 in | −1.69% |
| 285/45R18 | Minus 2 (18 in) | 28.10 in | +2.40% |
| 305/35R19 | Minus 1 (19 in) | 27.41 in | −0.13% |
| 295/35R19 | Minus 1 (19 in) | 27.13 in | −1.13% |
| 285/40R19 | Minus 1 (19 in) | 27.98 in | +1.95% |
| 285/35R19 | Minus 1 (19 in) | 26.85 in | −2.14% |
| 285/30R21 | Plus 1 (21 in) | 27.73 in | +1.06% |
| 345/25R21 | Plus 1 (21 in) | 27.79 in | +1.28% |
| 295/30R21 | Plus 1 (21 in) | 27.97 in | +1.92% |
| 355/25R21 | Plus 1 (21 in) | 27.99 in | +1.99% |
Vehicles approved with 315/30R20 tires
Models whose Swiss type approval lists 315/30R20 as a standard or optional size (44 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 20-inch sizes
Reading the 315/30R20 size
- 315 — section width in millimetres (12.40 in).
- 30 — aspect ratio: the sidewall is 30 % of the width, 94.5 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.