About RollingSpec

RollingSpec provides free, browser-based calculators for tire and wheel dimensions — tire size comparison, tire diameter, and wheel offset. There's no sign-up, no app to install, and no data uploaded: every calculation runs locally in your browser using standard geometry formulas based on published tire and wheel size conventions.

These tools are intended as a quick reference for comparing nominal dimensions. They do not replace manufacturer specifications, a fitment check by a qualified tire or wheel professional, or your vehicle owner's manual.