265/40R21 tire size
A 265/40R21 tire is 29.35 inches (745.4 mm) tall, 10.43 in (265 mm) wide and fits a 21-inch wheel. In inch notation it is roughly a 29.3x10.4R21 — a "29-inch" tire.
| Overall diameter | 29.35 in | 745.4 mm |
|---|---|---|
| Section width | 10.43 in | 265 mm |
| Sidewall height | 4.17 in | 106.0 mm |
| Circumference | 92.19 in | 2,342 mm |
| Revolutions | 687.2 per mile | 427.0 per km |
| Rim diameter | 21 in | 533.4 mm |
Compare 265/40R21 with another size
Alternative sizes on the same 21-inch wheel
Sizes in use within ±3 % of the overall diameter of 265/40R21:
Plus and minus sizes for 265/40R21
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 265/50R19 | Minus 2 (19 in) | 29.43 in | +0.30% |
| 295/45R19 | Minus 2 (19 in) | 29.45 in | +0.36% |
| 235/55R19 | Minus 2 (19 in) | 29.18 in | −0.58% |
| 285/45R19 | Minus 2 (19 in) | 29.10 in | −0.85% |
| 265/45R20 | Minus 1 (20 in) | 29.39 in | +0.15% |
| 295/40R20 | Minus 1 (20 in) | 29.29 in | −0.19% |
| 235/50R20 | Minus 1 (20 in) | 29.25 in | −0.32% |
| 305/40R20 | Minus 1 (20 in) | 29.61 in | +0.89% |
| 265/35R22 | Plus 1 (22 in) | 29.30 in | −0.15% |
| 315/30R22 | Plus 1 (22 in) | 29.44 in | +0.32% |
| 305/30R22 | Plus 1 (22 in) | 29.20 in | −0.48% |
| 275/35R22 | Plus 1 (22 in) | 29.58 in | +0.79% |
Vehicles approved with 265/40R21 tires
Models whose Swiss type approval lists 265/40R21 as a standard or optional size (431 approvals in total). Always check your own vehicle's placard or papers.
- Porsche Macan
- Maserati Levante
- Mercedes-Benz R-Class
- Bentley Continental
- BMW X3
- BMW X4
- Mercedes-Benz EQS
- Mercedes-Benz GLC
- Bentley Mulsanne
- Mercedes-Benz GLE
- Zeekr 7X
- Mercedes-Benz ML
- Bentley Flying
- Ford Edge
- Bentley Conti
- Lotus Emeya
- MG IM6
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
- 245/35R21 (−5.4%)
- 245/40R21 (−2.1%)
- 245/45R21 (+1.1%)
- 255/35R21 (−4.5%)
- 255/40R21 (−1.1%)
- 255/45R21 (+2.3%)
- 255/50R21 (+5.8%)
- 265/30R21 (−7.1%)
- 265/35R21 (−3.6%)
- 265/45R21 (+3.6%)
- 275/30R21 (−6.3%)
- 275/35R21 (−2.6%)
- 275/40R21 (+1.1%)
- 275/45R21 (+4.8%)
- 275/50R21 (+8.5%)
- 285/30R21 (−5.5%)
- 285/35R21 (−1.7%)
- 285/40R21 (+2.1%)
- 285/45R21 (+6.0%)
Reading the 265/40R21 size
- 265 — section width in millimetres (10.43 in).
- 40 — aspect ratio: the sidewall is 40 % of the width, 106.0 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.