225/45R18 tire size
A 225/45R18 tire is 25.97 inches (659.7 mm) tall, 8.86 in (225 mm) wide and fits a 18-inch wheel. In inch notation it is roughly a 26.0x8.9R18.
| Overall diameter | 25.97 in | 659.7 mm |
|---|---|---|
| Section width | 8.86 in | 225 mm |
| Sidewall height | 3.99 in | 101.3 mm |
| Circumference | 81.59 in | 2,073 mm |
| Revolutions | 776.5 per mile | 482.5 per km |
| Rim diameter | 18 in | 457.2 mm |
Compare 225/45R18 with another size
Alternative sizes on the same 18-inch wheel
Sizes in use within ±3 % of the overall diameter of 225/45R18:
Plus and minus sizes for 225/45R18
| Size | Wheel | Diameter | Difference |
|---|---|---|---|
| 195/65R16 | Minus 2 (16 in) | 25.98 in | +0.03% |
| 215/60R16 | Minus 2 (16 in) | 26.16 in | +0.71% |
| 225/55R16 | Minus 2 (16 in) | 25.74 in | −0.88% |
| 205/60R16 | Minus 2 (16 in) | 25.69 in | −1.11% |
| 255/45R17 | Minus 1 (17 in) | 26.04 in | +0.24% |
| 205/55R17 | Minus 1 (17 in) | 25.88 in | −0.36% |
| 225/50R17 | Minus 1 (17 in) | 25.86 in | −0.44% |
| 195/60R17 | Minus 1 (17 in) | 26.21 in | +0.92% |
| 255/35R19 | Plus 1 (19 in) | 26.03 in | +0.21% |
| 225/40R19 | Plus 1 (19 in) | 26.09 in | +0.44% |
| 245/35R19 | Plus 1 (19 in) | 25.75 in | −0.85% |
| 265/35R19 | Plus 1 (19 in) | 26.30 in | +1.27% |
| 255/30R20 | Plus 2 (20 in) | 26.02 in | +0.20% |
| 245/30R20 | Plus 2 (20 in) | 25.79 in | −0.71% |
| 225/35R20 | Plus 2 (20 in) | 26.20 in | +0.88% |
| 265/30R20 | Plus 2 (20 in) | 26.26 in | +1.11% |
Vehicles approved with 225/45R18 tires
Models whose Swiss type approval lists 225/45R18 as a standard or optional size (12,175 approvals in total). Always check your own vehicle's placard or papers.
- BMW 3 Series
- BMW 4 Series
- BMW 2 Series
- Audi A4
- Mercedes-Benz C-Class
- Volkswagen Touran
- SEAT Alhambra
- Skoda Octavia
- Volkswagen Sharan
- Fiat 500X
- Opel Insignia
- Saab 9-3
- Mercedes-Benz A-Class
- BMW X1
- Renault Laguna
- Alfa Romeo Giulia
- Volkswagen Caddy
- Jaguar XE
- Mercedes-Benz CLA
- Mazda 6
- Opel Astra
- Nissan Juke
- Hyundai i40
- Volkswagen Golf
- Citroen DS4
- Opel Vectra
- MINI Cooper
- SEAT Leon
- Renault Scenic
- Audi S4
- Mercedes-Benz B-Class
- Toyota Avensis
- Volvo V40
- BMW Z4
- Honda Accord
- Audi A3
- Citroen C4 Picasso
- Alpina B4
- Ford Tourneo Connect
- Alpina B3
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 18-inch sizes
- 205/40R18 (−5.8%)
- 205/45R18 (−2.7%)
- 205/55R18 (+3.5%)
- 215/35R18 (−7.9%)
- 215/40R18 (−4.6%)
- 215/45R18 (−1.4%)
- 215/50R18 (+1.9%)
- 215/55R18 (+5.2%)
- 225/35R18 (−6.8%)
- 225/40R18 (−3.4%)
- 225/50R18 (+3.4%)
- 225/55R18 (+6.8%)
- 235/35R18 (−5.8%)
- 235/40R18 (−2.2%)
- 235/45R18 (+1.4%)
- 235/50R18 (+4.9%)
- 235/55R18 (+8.5%)
- 245/35R18 (−4.7%)
- 245/40R18 (−1.0%)
- 245/45R18 (+2.7%)
- 245/50R18 (+6.4%)
Reading the 225/45R18 size
- 225 — section width in millimetres (8.86 in).
- 45 — aspect ratio: the sidewall is 45 % of the width, 101.3 mm.
- R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
- 18 — fits a 18-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.