255/40R23 tire size
A 255/40R23 tire is 31.03 inches (788.2 mm) tall, 10.04 in (255 mm) wide and fits a 23-inch wheel. In inch notation it is roughly a 31.0x10.0R23 — a "31-inch" tire.
| Overall diameter | 31.03 in | 788.2 mm |
|---|---|---|
| Section width | 10.04 in | 255 mm |
| Sidewall height | 4.02 in | 102.0 mm |
| Circumference | 97.49 in | 2,476 mm |
| Revolutions | 649.9 per mile | 403.8 per km |
| Rim diameter | 23 in | 584.2 mm |
Compare 255/40R23 with another size
Alternative sizes on the same 23-inch wheel
Sizes in use within ±3 % of the overall diameter of 255/40R23:
Plus and minus sizes for 255/40R23
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 255/50R21 | Minus 2 (21 in) | 31.04 in | +0.03% |
| 285/45R21 | Minus 2 (21 in) | 31.10 in | +0.22% |
| 275/45R21 | Minus 2 (21 in) | 30.74 in | −0.93% |
| 305/40R21 | Minus 2 (21 in) | 30.61 in | −1.37% |
| 255/45R22 | Minus 1 (22 in) | 31.04 in | +0.01% |
| 285/40R22 | Minus 1 (22 in) | 30.98 in | −0.18% |
| 295/40R22 | Minus 1 (22 in) | 31.29 in | +0.84% |
| 275/40R22 | Minus 1 (22 in) | 30.66 in | −1.19% |
Vehicles approved with 255/40R23 tires
Models whose Swiss type approval lists 255/40R23 as a standard or optional size (10 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 23-inch sizes
Reading the 255/40R23 size
- 255 — section width in millimetres (10.04 in).
- 40 — aspect ratio: the sidewall is 40 % of the width, 102.0 mm.
- R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
- 23 — fits a 23-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.