About FitMyTire

FitMyTire exists because most tire calculators give you a number with no explanation. We think the math is the useful part — whether a size fits your wheels, how far off your speedometer will read, what you gain and give up — so every tool here shows its work and links to a plain-English explanation.

The calculations follow standard ISO metric tire notation and the same fitment guidelines used by wheel and tire retailers. They're estimates for planning, not a substitute for a professional fitment check — always confirm offset and clearance for your specific vehicle before buying.

The tools

• Rim & Tire Fitment — which tire widths fit your wheel
• Tire Size Comparison — side-by-side dimensions and speedometer impact
• mm → Inches Converter — metric sizes in plain inches