Bilal Khan
Founder and editor of TiresTreads.com, an independent site of free tire size tools and plain-language tire safety guides.
About Bilal Khan
Bilal Khan is the founder and editor of TiresTreads.com. The site publishes a tire size calculator, a 3D size comparison viewer and a growing set of guides on tire sizing, wear, age and wet-weather safety.
TiresTreads exists to make tire numbers easier to understand: what a size code means, what happens to your speedometer when you change tire diameter, and when a tire has reached the end of its safe life.
How the Tools and Guides Are Made
We describe only what the tools actually do, so you can judge them for yourself.
Standard tire-size formulas
The calculator uses the standard metric size designation: sidewall height = section width × aspect ratio, and overall diameter = rim diameter + 2 × sidewall height. The formulas are shown on the calculator page.
Speedometer difference
The speedometer difference is worked out from the ratio of the two overall diameters, and shown in a table from 20 to 90 mph.
Sources
Where a guide relies on a specific source, such as NASA’s hydroplaning research or NHTSA tire information, we cite it at the bottom of the page. We are adding citations to every guide.
Safety first
Tire size, load rating and wheel torque are safety items. Our tools and guides do not replace your owner’s manual, your door-jamb placard or an inspection by a professional.
Topics We Cover
Tire size and plus sizing
How to compare tire sizes, convert between metric and inches, and what changes when you move to larger wheels.
Wear patterns and tread depth
How to read uneven wear, measure tread depth, and decide when tires should be replaced.
Tire age and DOT codes
How to read the four-digit DOT date and why tire age matters even when the tread looks fine.
Wet grip and seasonal tires
Hydroplaning, tire pressure, and how all-season, all-weather and winter tires differ.
Editorial Standards and Independence
- TiresTreads is independent. We do not accept paid reviews or sponsored placement from tire brands or retailers.
- If we ever show ads or use affiliate links, we will label them clearly.
- Our guides are general education. They are not a substitute for your vehicle’s owner’s manual or professional advice.
- If you find a mistake, please tell us. We correct errors and update the page.
Tools and Guides
Contact
Found a mistake in a calculation, have a question about a guide, or want to suggest a tool? Send us a message.
Email info@tirestreads.com Contact page