Tire calculators & tools
Free tools for tire decisions: compatibility check, plus-size calculator, speedometer-error estimator, install-cost comparison, and cost-per-mile analysis.
Tire size compatibility calculator
Will this alternative size fit? Overall-diameter delta, speedometer error, and load/speed verdict against the ±3% safe-fit rule.
Plus-size calculator
Safe Plus-1, Plus-2, and Plus-3 candidate sizes with sidewall and ride-comfort impact.
Speedometer error calculator
True ground speed and odometer drift after a tire-size change. SAE J1349 reference.
Tire install cost calculator
Mount, balance, TPMS service, and disposal — by state and retailer.
Tire mileage value calculator
Cost per mile based on warranty miles and price. Compare any two tires.