345/25R21 tire size
A 345/25R21 tire is 27.79 inches (705.9 mm) tall, 13.58 in (345 mm) wide and fits a 21-inch wheel. In inch notation it is roughly a 27.8x13.6R21 — a "28-inch" tire.
| Overall diameter | 27.79 in | 705.9 mm |
|---|---|---|
| Section width | 13.58 in | 345 mm |
| Sidewall height | 3.40 in | 86.3 mm |
| Circumference | 87.31 in | 2,218 mm |
| Revolutions | 725.7 per mile | 450.9 per km |
| Rim diameter | 21 in | 533.4 mm |
Compare 345/25R21 with another size
Alternative sizes on the same 21-inch wheel
Sizes in use within ±3 % of the overall diameter of 345/25R21:
Plus and minus sizes for 345/25R21
Vehicles approved with 345/25R21 tires
Models whose Swiss type approval lists 345/25R21 as a standard or optional size (15 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 345/25R21 size
- 345 — section width in millimetres (13.58 in).
- 25 — aspect ratio: the sidewall is 25 % of the width, 86.3 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.