Free Tire Size Calculator

This tool computes geometry from the tire size text entered only. It does not know your vehicle, does not inspect your tires, and does not look up manufacturer specifications.

The calculator results are based on the mathematical equations of the tire sizes entered, not a guarantee of fitment. Diameter difference under the common 3% guideline is not a fitment guarantee. Modifying tire size can affect suspension, brake caliper and body clearance, speedometer accuracy, and ABS/ESC calibration. Always check your vehicle's owner manual, the tire placard on the driver's door jamb, and consult a qualified installer before purchase.