The 235/45R18 is a common tire size for midsize sedans such as Toyota Camry, Honda Accord, and Hyundai Sonata.
With a 105.8 mm sidewall (45% aspect ratio), this tire offers a balanced blend of ride comfort and handling precision — versatile for both city driving and spirited cornering.
This is one of the most popular tire sizes for 18" rims, frequently used as a reference point when comparing speedometer accuracy across similar sizes.
When replacing, verify that your wheel well can accommodate the 668.7 mm overall diameter. Keep speedometer deviation within ±3% for safety and legal compliance.
| Tire Code | 235/45R18 |
| Section Width | 235 mm |
| Aspect Ratio | 45% |
| Rim Diameter | 18" |
| Sidewall Height | 105.8 mm |
| Overall Diameter | 668.7 mm / 26.33" |
| Circumference | 2100.8 mm / 82.71" |
| Revolutions per km | 476.0 |
| Revolutions per mile | 766.1 |
| Tire Code | OD (mm) | Δ mm | Δ % | Speedo at 100 km/h |
|---|---|---|---|---|
| 235/45R17 | 643.3 | -25.4 | -3.8% | 103.9 |
| 235/40R18 | 645.2 | -23.5 | -3.5% | 103.6 |
| 225/45R18 | 659.7 | -9.0 | -1.3% | 101.4 |
| 235/45R18 (current) | 668.7 | — | — | 100.0 |
| 245/45R18 | 677.7 | +9.0 | +1.3% | 98.7 |
| 235/45R19 | 694.1 | +25.4 | +3.8% | 96.3 |
| 235/55R18 | 715.7 | +47.0 | +7.0% | 93.4 |