1. Width:
- Place the measuring tape across the widest point of the tire, usually the sidewall.
- Measure from the outermost point of the sidewall on one side to the outermost point on the other side.
- The width is typically expressed in inches or millimeters (e.g., 12R22.5, where "12" represents the width in inches).
2. Height:
- Position the measuring tape at the bottom of the tire, touching the ground or surface.
- Measure vertically from the bottom to the top of the tire, including any tread.
- The height is also expressed in inches or millimeters (e.g., 12R22.5, where "22.5" represents the height in inches).
3. Rim Size:
- Locate the rim, which is the metal circle that holds the tire onto the wheel.
- Measure the diameter of the rim, not including the tire, from one edge to the other.
- The rim size is typically expressed in inches (e.g., 12R22.5, where "22.5" represents the rim size in inches).
4. Aspect Ratio:
- While you don't directly measure the aspect ratio, you can calculate it using the width and height measurements.
- The aspect ratio is the height of the tire's sidewall as a percentage of the tire's width.
- To calculate the aspect ratio, divide the height measurement by the width measurement and multiply by 100.
For example, if the width measurement is 12 inches and the height measurement is 22.5 inches, the aspect ratio can be calculated as follows:
Aspect ratio = (22.5 inches / 12 inches) * 100
Aspect ratio = 1.875 * 100
Aspect ratio = 187.5
In this example, the aspect ratio is 187.5, which means that the sidewall height of the tire is approximately 187.5% of the tire's width.
Remember to cross-check your measurements with the tire's sidewall markings, which usually provide the exact tire size information.
