타이어 외경·인치업 계산기

By entering the specifications of your current tires and the tires you intend to replace them with, you can immediately compare the total outer diameter and the difference.

Key Features

• Easily input specifications like 225/55R17 in a single line

• Calculate the difference between the total outer diameter and circumference

• Calculate estimated ride height change

• Compare actual speed with the speedometer reading of 100 km/h

• Check tire rotations per kilometer

• Recommend candidates with similar outer diameters within the same wheel diameter

• Save and reload recent comparison records

• Share calculation results

• Supports Dark Mode and Landscape mode

Quick Inch-up Comparison

You can check the difference between two specifications in mm and percentage without having to search through complex tables. For example, it shows how much the outer diameter, ride height, and speedometer display theoretically change when switching from 225/55R17 to 235/50R18.

Clear Calculation Criteria

The total outer diameter is calculated using the formula: Wheel Diameter × 25.4 + 2 × Section Width × Aspect Ratio ÷ 100. Recommended specifications are sorted based solely on the difference in outer diameter. Please be sure to check.

The ±3% indication in the app is a general reference value and does not guarantee installation compatibility or safety. Wheel width and offset, fender/suspension interference, load index, speed rating, tire pressure, vehicle manufacturer approval, and relevant regulations must be verified separately. Please consult the vehicle/tire manufacturer or a specialist shop before final installation.