Tire Size Calculator

This calculator helps you determine the key specifications of a tire based on its size designation

Input Parameters

Calculation Results

Calculation Results

Sidewall Height:

-

Aspect Ratio:

-

Wheel Diameter:

-

Revolutions Per Mile:

-

Calculation Formula

Overall Diameter = (Width × Aspect Ratio ÷ 25.4) × 2 + Wheel Diameter

Where:
Width = First number in tire size
Aspect Ratio = Second number in tire size (after "/")
Wheel Diameter = Last number in tire size (after "R")
Revolutions Per Mile = 63,360 ÷ Overall Diameter

Tire Size Calculator Calculator Usage Guide

Learn how to use the Tire Size Calculator and understand tire size specifications

How to Use This Calculator

  1. Enter the tire size in the format Width/AspectRatioRWheelDiameter. For example, 205/55R16.
  2. Click the "Calculate" button to see the breakdown of the tire's specifications.
  3. The calculator will display the sidewall height, aspect ratio, wheel diameter, and revolutions per mile.

Understanding Tire Size Designations

Tire sizes are designated using a standardized format that provides key information about the tire:

205/55R16

  • 205 - Tire Width in millimeters
  • 55 - Aspect Ratio (height of the tire's cross-section is 55% of the width)
  • R - Radial construction indicator
  • 16 - Wheel Diameter in inches

What the Results Mean

  • Sidewall Height - The height of the tire's sidewall in inches
  • Aspect Ratio - The tire's height-to-width ratio as a percentage
  • Wheel Diameter - The diameter of the wheel the tire is designed to fit
  • Revolutions Per Mile - How many times the tire will rotate in one mile at the given size