Free Tire Size Tools and Plain-Language Tire Safety Guides
TiresTreads.com is an independent site that helps drivers compare tire sizes and understand tire wear, age and wet-weather safety, without the sales pitch.
Tires are the only part of your car that touches the road. Advice about them should be clear, careful and honest about what it cannot tell you.
TiresTreads.com was started to make tire sizes, sidewall markings and the real cost of new tires easier to understand, using tools that show their math.
Bilal Khan
Bilal Khan is the founder and editor of TiresTreads.com. He runs the site and writes its guides.
About Bilal Khan →What We Stand For
Clear Tire Math
Our calculator uses the standard metric tire-size formulas to compare overall diameter, sidewall height, circumference and speedometer difference. The formulas are shown on the calculator page, so you can check them yourself.
Safety First
We explain the common ±3% diameter rule of thumb, and we remind readers that tire size, load rating and wheel torque must be checked against the owner’s manual and the door-jamb placard.
Cost Transparency
Our buying guides explain the full out-the-door cost of tires, including mounting, balancing and disposal, and how to read the DOT date so shoppers can compare real prices.
Independence
TiresTreads is independent. We are not owned by a tire maker, dealership or retailer, and we do not accept paid reviews or sponsored placement. If that ever changes, we will say so clearly.
Where Our Information Comes From
We try to be clear about our sources. Where a guide relies on a specific source, we cite it at the bottom of the page, and we are adding citations to every guide. In general we draw on:
- Tire and Rim Association (TRA) and ETRTO: industry bodies that publish tire and rim dimension standards. Our size formulas follow the standard metric size designation.
- NHTSA: US federal tire safety information, including how to read the DOT tire identification number.
- Vehicle and tire makers: owner’s manuals and manufacturer guidance for safety-critical values such as pressure, load rating and wheel torque.
- Published research: for example, NASA’s hydroplaning research (Horne and Dreher, 1963), which we cite in our hydroplaning guide.
Our guides are for general education. They do not replace your owner’s manual or advice from a qualified technician. Please read our Safety Disclaimer.
Questions, Feedback or Corrections?
If you have a question, a suggestion, or you think a calculation or guide contains a mistake, please tell us. We read every message and correct errors when we find them.
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