Tire Size Calculator

MORE SIZE SYSTEMS. THE SAME DEEP WEIGHT MODEL. Compare passenger-car, light-truck/high-flotation and motorcycle tire sizes in one focused calculator. TireCalc supports modern metric sizing, legacy full-profile sizes, LT direct-diameter designations, and catalog-backed motorcycle metric, inch, alphabetic and ATV/UTV formats. GO BEYOND SIZE: ROTATING WEIGHT Tire and wheel weight is rotating, unsprung mass—not just another number on a scale. For car and light-truck comparisons, enter each tire and wheel weight plus vehicle weight, peak torque and 0–60 time. The app models the total mass change and rotational inertia of all four assemblies, then displays an estimated equivalent vehicle-weight range during acceleration. Enthusiasts can compare lightweight setups quantitatively; first-time buyers can see why reducing a few pounds at each wheel may matter more than the scale alone suggests. The result is shown as a range across several mass-distribution assumptions, not as a misleading single claim. One-time purchase. No ads, subscriptions or data collection. COMPARE THE NUMBERS • Overall diameter and circumference • Section width and sidewall height • Actual vehicle speed at 60 and 100 • Load index and speed rating • Tire and wheel weight • Four-wheel mass change, rotational inertia and modeled equivalent vehicle-weight range MORE WAYS TO ENTER A TIRE • Modern passenger/LT metric: widths from 125 through 405 and profiles from 20 through 85 • Legacy full-profile: exact table-based dimensions, including applicable “82-series” equivalents • LT/high-flotation: direct overall diameter, width and rim designations • Motorcycle: catalog-backed metric, inch, alphabetic and ATV/UTV sizes, including structure and rim-code distinctions FIND CAR AND LT SIZE ALTERNATIVES Set allowable changes for rim diameter, section width and circumference. TireCalc generates alternatives you can select and compare instantly. SEE THE DIFFERENCE Use scaled tire diagrams in side-by-side or half-circle mode to understand how two setups differ visually. Switch between imperial and metric measurements at any time. BUILT-IN GUIDANCE The Size Guide explains each supported format and its limits. A valid designation is not vehicle fitment approval: load, speed, rim, clearance and manufacturer requirements still apply. Never translate a motorcycle rim code into inches by appearance, and never use a calculated result as permission to mount a tire. Always confirm final tire and wheel compatibility with the vehicle or motorcycle manufacturer, the tire manufacturer, and a qualified tire professional before purchasing or installing equipment.