Tire Size Calculator – Decode & Compare Tire Codes
Use this free Tire Size Calculator to decode tire codes (like 205/55R16), find section width, aspect ratio, wheel diameter, section height, and overall tire diameter. Compare two tires to see the difference in size and compatibility. Visualize the difference for safer and smarter tire choices.
How to Read a Tire Code
- Section Width: The first 3 digits (e.g., 205) – width in mm.
- Aspect Ratio: The 2 digits after the slash (e.g., 55) – sidewall height as % of width.
- Construction: The letter (usually R for radial).
- Wheel Diameter: The last number (e.g., 16) – rim size in inches.
How Tire Size is Calculated
- Section Height: Aspect Ratio × Section Width
- Tire Diameter: Wheel Diameter + 2 × Section Height
Why Tire Size Matters
- Ensures speedometer and odometer accuracy.
- Maintains proper handling, safety, and ride comfort.
- Prevents excessive wear on suspension and brakes.
- Helps choose compatible tires for upgrades or replacements.
Tips for Choosing Tires
- Stay within 3% of the original tire diameter for best results.
- Replace all tires together or at least both on the same axle.
- Check the load index and speed rating for your vehicle.
- Consult your vehicle manual or a tire professional for advice.