235/40R18 in inches
A 235/40R18 tire stands 25.4 inches tall and is 9.3 inches wide. It fits an 18-inch wheel.
Tall
25.4″
645 mm
Wide
9.3″
235 mm
Wheel
18″
rim diameter
Cars that come with 235/40R18
Similar-height sizes
Within 3% of 235/40R18, so your speedometer stays close.
| Size | Height | vs 235/40R18 | |
|---|---|---|---|
| 215/50R17 | 25.5″ | +0.2%needs 17″ wheels | Compare |
| 215/55R16 | 25.3″ | −0.4%needs 16″ wheels | Compare |
| 265/30R19 | 25.3″ | −0.6%needs 19″ wheels | Compare |
| 225/40R18 | 25.1″ | −1.2% | Compare |
| 245/40R18 | 25.7″ | +1.2% | Compare |
| 245/35R19 | 25.8″ | +1.4%needs 19″ wheels | Compare |
| 245/30R20 | 25.8″ | +1.5%needs 20″ wheels | Compare |
| 195/65R15 | 25.0″ | −1.7%needs 15″ wheels | Compare |
How 235/40R18 is measured
| Measurement | Inches | Millimetres |
|---|---|---|
| Overall height (diameter) | 25.40 | 645 |
| Tread width | 9.25 | 235 |
| Sidewall height | 3.70 | 94 |
| Distance per turn (circumference) | 79.8 | 2027 |
| Turns per mile | 794 | |
The first number (235) is the width in millimetres. The second (40) means the sidewall is 40% as tall as the tire is wide. The last (18) is the wheel size in inches. More on reading a tire size.