Tire Size Calculator +
Compare, Offset & Speedo Error
About
Calculate tire size differences, speedometer errors, and wheel offset changes. Compare tire dimensions, find alternative sizes, and visualize wheel fitment. Save your car's tire sizes for quick access.
What's New in Tire Size Calculator +
1.2.6
October 22, 2026
• If the ad that opens with the app can't appear, the start screen won't freeze anymore; the app moves past that ad and opens “Compare”.
Developer apps
FAQ
What is the main function of Tire Size Calculator +?
Tire Size Calculator + helps users compare different tire sizes, calculate potential speedometer and odometer errors, and analyze how new wheel offsets will affect fitment. It provides detailed comparisons of diameter, sidewall height, and circumference.
Does Tire Size Calculator + have ads?
Yes, Tire Size Calculator + contains advertisements. This allows the app to be offered to users for free.
What devices is Tire Size Calculator + available on?
Tire Size Calculator + is currently supported on iPhone devices. Information on Android availability is not provided.
How accurate are the calculations in Tire Size Calculator +?
The app provides geometric estimates based on tire size markings. Actual tire width can vary with the rim, and the app advises confirming fitment with a vehicle manual or professional.
Can I save my car's tire information in Tire Size Calculator +?
Yes, the 'My Garage' feature allows you to save the tire sizes for your cars. You can then load these saved sizes with a single tap for easy comparison.
What kind of tire sizes can be compared?
The app supports both metric sizes (e.g., 225/45R17) and flotation sizes (e.g., 31x10.50R15). You can also switch between millimeters and inches for measurements.
How does Tire Size Calculator + handle wheel offset calculations?
You can input the rim width and offset for both current and new wheels. The app will then show how many millimeters the outer edge moves out, how much closer the inner edge gets to suspension, and changes in backspacing.
What is the age rating for Tire Size Calculator +?
Tire Size Calculator + has an age rating of 17+. This is likely due to the technical nature of the automotive calculations involved.
