255/45R20 tire size
A 255/45R20 tire is 29.04 inches (737.5 mm) tall, 10.04 in (255 mm) wide and fits a 20-inch wheel. In inch notation it is roughly a 29.0x10.0R20 — a "29-inch" tire.
| Overall diameter | 29.04 in | 737.5 mm |
|---|---|---|
| Section width | 10.04 in | 255 mm |
| Sidewall height | 4.52 in | 114.8 mm |
| Circumference | 91.22 in | 2,317 mm |
| Revolutions | 694.6 per mile | 431.6 per km |
| Rim diameter | 20 in | 508.0 mm |
Compare 255/45R20 with another size
Alternative sizes on the same 20-inch wheel
Sizes in use within ±3 % of the overall diameter of 255/45R20:
Plus and minus sizes for 255/45R20
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 255/55R18 | Minus 2 (18 in) | 29.04 in | +0.03% |
| 235/60R18 | Minus 2 (18 in) | 29.10 in | +0.23% |
| 285/50R18 | Minus 2 (18 in) | 29.22 in | +0.64% |
| 225/60R18 | Minus 2 (18 in) | 28.63 in | −1.40% |
| 255/50R19 | Minus 1 (19 in) | 29.04 in | +0.01% |
| 285/45R19 | Minus 1 (19 in) | 29.10 in | +0.22% |
| 235/55R19 | Minus 1 (19 in) | 29.18 in | +0.49% |
| 275/45R19 | Minus 1 (19 in) | 28.74 in | −1.00% |
| 255/40R21 | Plus 1 (21 in) | 29.03 in | −0.01% |
| 295/35R21 | Plus 1 (21 in) | 29.13 in | +0.33% |
| 285/35R21 | Plus 1 (21 in) | 28.85 in | −0.62% |
| 235/45R21 | Plus 1 (21 in) | 29.33 in | +1.00% |
| 255/35R22 | Plus 2 (22 in) | 29.03 in | −0.03% |
| 295/30R22 | Plus 2 (22 in) | 28.97 in | −0.23% |
| 305/30R22 | Plus 2 (22 in) | 29.20 in | +0.58% |
| 265/35R22 | Plus 2 (22 in) | 29.30 in | +0.92% |
Vehicles approved with 255/45R20 tires
Models whose Swiss type approval lists 255/45R20 as a standard or optional size (2,621 approvals in total). Always check your own vehicle's placard or papers.
- Audi Q5
- Volvo XC60
- Mercedes-Benz GLC
- Audi SQ5
- BMW 7 Series
- Alfa Romeo Stelvio
- BMW X3
- BMW X4
- Volkswagen ID.4
- Rolls-Royce Ghost
- Skoda Enyaq
- Volvo XC90
- Renault Espace
- Audi Q4
- Maserati Grecale
- Hyundai Santa Fe
- Volkswagen ID.5
- Mercedes-Benz EQS
- Nissan Ariya
- Rolls-Royce Wraith
- Tesla Model X
- BMW i7
- Nissan X-Trail
- Rolls-Royce Dawn
- Kia EV6
- Hyundai Ioniq 5
- Mercedes-Benz GLE
- Kia Sorento
- Ford Edge
- Smart 5
- Mercedes-Benz ML
- Mercedes-Benz EQC
- Alpina XD3
- XPeng G6
- Alpina XD4
- Seres 5
- Chrysler 300C
- MG IM6
- Lotus Emeya
- Lexus RZ450E
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
- 235/35R20 (−8.8%)
- 235/40R20 (−5.6%)
- 235/45R20 (−2.4%)
- 235/50R20 (+0.7%)
- 235/55R20 (+3.9%)
- 245/35R20 (−7.9%)
- 245/40R20 (−4.5%)
- 245/45R20 (−1.2%)
- 245/50R20 (+2.1%)
- 255/35R20 (−6.9%)
- 255/40R20 (−3.5%)
- 255/50R20 (+3.5%)
- 255/55R20 (+6.9%)
- 265/35R20 (−6.0%)
- 265/40R20 (−2.4%)
- 265/45R20 (+1.2%)
- 265/50R20 (+4.8%)
- 275/35R20 (−5.0%)
- 275/40R20 (−1.3%)
- 275/45R20 (+2.4%)
- 275/50R20 (+6.2%)
- 275/55R20 (+9.9%)
Reading the 255/45R20 size
- 255 — section width in millimetres (10.04 in).
- 45 — aspect ratio: the sidewall is 45 % of the width, 114.8 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.