You don't have to be a tire professional to use these free tire size calculators. You just have to know how to read the information. When you enter a tire size into a tire size calculator, a variety of information is returned.

Tire Section Width: The tire's width can be important in preventing clearance issues. A wide tire could rub on the wheel well or suspension components, particularly when the wheels are turned. A wider tire also lowers your gas mileage.

Rim Width Range: Each tire size can only fit on wheels within a particular width range. If the tire is too wide or too narrow for your wheels, there is extra stress on the tire which could result in tire failure.

Overall Diameter: Your tire's overall diameter is very important as tires with different heights rotate at different speeds. This would interfere with your speedometer and odometer. It could interfere with ABS brakes and other vehicle parts. You should keep your overall tire height within 3% of the height of your original stock tires.

Revolutions Per Mile: A taller tire has a larger circumference. So it covers more distance with each rotation of the wheel axle. This means a taller tire will have lower rotations per mile. The revolutions per mile is used in calculations by various vehicle components such as the speedometer & odometer.

Speedometer Difference: If you change your tire size and it is not the same as stock tire height, your speedometer and odometer will be inaccurate. Tire size calculators will show just how much your speedometer will be thrown off. A taller tire will make your speedometer read slower than actual speed. Conversely a shorter tire will make your speedometer read faster than actual speed.

That is the most important information that you can view with a tire size calculator. Most tire calculators offer a lot of other information, but that is primarily for advanced users. Your main concern is usually finding a tire size that is very close to stock height. After doing some research, always consult a tire professional before switching tire sizes.